I tried to explain to my girlfriend why I’ve been watching videos on late 90’s to early 00’s enterprise networking equipment and… I have no idea but please keep them coming lol
Its where "it" all started to form. And it hasnt changed much. For example, auth protocols like PPP from the 90s are still used every day in modern fiber connections. I love this channel :)
Working for an ISP in the 90's, we had dozens of 2511's handling inbound dialup PPP sessions, each with its own discrete rack modem. A call group (POP) might have a hundred or more modems. The core router at each POP was a Cisco AGS+, with ISDN being used for inter-POP links initially, later moving to Nx64k sync serial, then frame relay, then ATM. Dialup access moved to the 5200 (which had 60 discrete modem DSP chips in 2 rack units - the heat coming out was diabolical), then the 5300 (which could handle up to 480 calls, no longer using a DSP-per-caller, if I remember correctly).
We used the Cisco 5200 and 5300 as well - "Access Server" (so 'AS5200' and 'AS5300'). Both were 2U, and had 48 and 96 modems per card, respectively, with multiple cards able to run in each unit. 'MICA' and "Microcom' modems (trunked in over T1 lines), I think the MICA modems had more trouble with low-quality lines.
The Serial Port is another RUclips channel that dives into enterprise gear from this era. They rebuilt exactly what you described: a dial-in ISP, with modems going into a terminal server via PPP, then out to "the internet". It's great to learn a bit more history from them.
Terminal servers still rock today So much hardware from storage to switches to power distribution stuff still needs serial port access. Especially when they fail. They were so expensive back then now they are so cheap. Thanks for the video
Long Live RS232! I use Moxa 16 and 32 port terminal servers to control TV's and other devices in commercial AV installs. Functions the same way - IP address + port#. Also use CAT6 to do all the runs. I could do a lot of it over IP, but RS232 always works! 99% of Commercial LED (and a fair number of consumer) TV's still come equipped with a serial port. (normally on a 1/8" TRS jack)
Thank you for pausing to explain the port mapping on Telnet to the physical serial ports on the devices and how things are connected. Really helps me grasp how things are stung together.
If you're in it for fun, having a second rack opens up the natural if not necessary opportunity to build out the racks as independent units that then need to be networked together and internally self-sufficient for things like these terminal servers
At work we're fortunate enough to have Avocent 8000 series concentrators. 48 ports, HTML5 interface, and auto detecting cable settings. Love them so much. They're absolutely rock solid. :D
Wow!! just wow! took me back 20 years to when I was studying for my cisco exams! the octopus cable setup using 2 C2509's was such a time saver!! thank you for bringing this back!!
Classic reverse telnet configuration. The 2500s are a throw back, they were the first router I touched in a networking vocational class I took growing up. Back at my first job I was supporting a retailer that had modems in each router for backup and OOB management, we had to use HyperTerminal to dial into the router for troubleshooting when the connection was down. Crazy thing that you can do with it is use them with a dial backup configuration if you setup a dialer interface. I always found a router serving an entire lan with a 56K modem that it auto dials a crazy idea as I only though of dialup internet before from the point of a single host calling out.
We used to use these as emergency access paths back when I worked at an ISP If routing stuffed up, we wouldn't exactly telnet into to a console. So we had a modem connected to a terminal server, connected to our core routers and the edge to our management network So if we stuffed something up, we didn't need remote hands to reboot the routers (which only worked if it was a config change obviously) we just dialled up a modem, hit the terminal server and jumped into what ever router my mentor broke :D
the config works that way because you can set a timeout to reboot, which means when sending big/important/complex changes over you can schedule the router to reboot in X mins if not cancelled. so if you send over some config changes that break connectivity to the router or anything else the changes will be reverted automatically by the timeout reboot. if everything is working, just cancel the reboot. saved my butt more than once.
It depends on IOS version now. Sometimes it works and sometimes it doesn't. I don't remember which version or what the difference was, but I remember working on Cisco 55A2s where commands weren't immediately active unless you ended configuration, and "copy run start" threw an error lol.
Finally a clabretro video that didn't have me shopping on ebay! We use Cisco at work. We use the Aux port on the routers in remote stations to connect to the console of a server or other router. I have several of those same brand AUI adapters that I got from work. They are very nicely made.
No, and I used them as late as 2013 for OOB access to our core network and routers in case of emergencies. I had to use it twice in the 5 years I had it there, using a 10Mpbs leased line from the DC when all 3 of our unlink went down and I wasn't on any of our peer networks. Fun times.
Cables with the same idea, i.e. one multi pin connector to several connectors with fewer pines, are used for stage lighting, and those are called whips :) (the stage lighting multi channel connector is called socapex)
The holy grail of terminal servers from the 2500 series is probably the as2511-rj which has 16x RJ45 serial ports built-in for the rollover cables. In my experience (10+ years ago), the 2500-series were rapidly going away and we mostly used the 2800-series with 4x octopus cables for lab use. Notably, there are HWIC-8A and HWIC-16A that also take octopus cables (CAB-HD8-ASYNC) which I think are a different connector.
What's funny is you mentioned Cisco being the 'standard' on serial ports, they wire their stuff differently. I work with SANs and when you have to connect to a controller via serial we always have to ask to make sure they aren't using a cisco serial console cable. ;)
Cisco is pretty much the standard across all networking consoles across all brands, but yeah storage and other categories decided to be different, for no apparent advantage. The worst I know of is plugging a "standard" Cisco console cable into an APC UPS resulting in an instant power off of the UPS and everything connected.
@@incandescentwithrage Glad I am not the only one who made that mistake, my go to story about how old APC UPSs aren't so Uninterruptable. BTW it wasn't just Cisco cables it happens with regular Null Modem cables I had to order the specific APC cable for it to work.
When running a pair of 2501, it was useful to connect the aux on each to the console of the other. This allowed using the partner to do disruptive upgrades, etc.
I used this on a pair of 2800s we deployed for an event, and thought I was pretty smart for figuring it out until I found out it's a pretty common thing that's been used on pairs of routers for ages.
The rollover cable literally flips pin 1 -> 8, 2 -> 7, 3 -> 6 and so on... It rolls the cable over. That's the kind of cable needed for the MRV around 4m10s. Recently dug up an identical AUI to RJ-45 adapter to show a friend, which is why I clicked the video... Now seeing many flashbacks to the start of my first career.
Also: Unless cisco has some special hardware that can flip the pins internally, it wouldn't work to connect two octopus RJ45 connectors to each other with a straight RJ45 female-female adapter, or more importantly it wouldn't work connecting the AUX port of two Cisco routers to each other, or for that sake the console port to each other. I.E. even when exclusively using cisco equipment you would need flipped and straight cables. Suggestion to @clabretro: Either make a simple adapter that breaks out each RJ45 pin to a banana jack or just something that you can put alligator clips on, to use with a multimeter, or get one of those RS232 debug thingies with a bunch of LEDs and whatnot, in order to find out what is going on when a serial connection don't work. Btw, flipped and non-flipped cables have been the bane of existence for any type of consumer electronics equipment that uses the same connector for signals in both directions, like for example a tape recorder. The SCART connectors (common on European TVs and whatnot) mostly solved this by defining the pins as in or out rather than things like record and play). However the older DIN connectors had pins defined as record and pins defined as playback, and in some cases you had to use crossover cables to copy between two tape recorders. In other cases you didn't need that, as some tape recorders only connected an output signal to the play pins while in playback, and otherwise used those pins as an extra recording input (with different signal levels - line level recording on the playback pins and microphone level recording on the recording pins)...
I had a 6 line BBS back in the mid 90's and used something call a boca board. it was an IDE card that had a fat cable that hooked up to a 16 port RJ45 breakout box and had 16 RJ45 to 25pin serial ports. it worked like a charm, and i have no idea how i did all that at 16
I haven't seen that name in a long time. Back around 2008 we were doing network upgrades after a large bank acquired a smaller one. Found an abandoned closet full of terminal servers. Apparently many years prior they were used for a different application, to link banker's dumb terminals back to the main office. Blockbuster video also used terminal servers. Each store ran a AlpahServer DS10 in the back and the front end ran a PC that booted DOS from a floppy disk. They ran this setup until they went out of business. Must have cost them a fortune to maintain.
Nit pick: IT was V35, but the V35 standard expired and thus it's "former v35". Anecdote: A friend had decided to never ever have to have anything to do with V35 in his IT career :D
MAU - Media Attachment Unit, it connects the port, the AUI to the actual network cable, the media. In the beginning, ethernet cable was a quite thick and almost inflexible cable, you didn't run this to your equipment, it stayed up in the suspended ceiling, or under a raised floor. You used an attachment box, or tap that 'spiked into' that cable, this tap box was then connected to your computer by a way friendlier flexible cable to the AUI port of your computer. Later on they came up with 'Thinnet' that used much thinner coax that was convenient to bring to the back or your computer, so we had these adapter boxes simular to yours, but with BNC connectors on them. Then came 10baseT with the modern RJ45 connectors, and the adapters you have.
And in particular with the transceiver/MAU a bit away from the device it was of course just a regular DA15 connector and thus way less risk och breaking the connector if you pull on it. This type of AUI cable can be used with transcievers/MAUs used in this video too! (Not 100% sure but I think that the locking mechanism is intentionally weaker than the regular d-sub screws just so that you "only" screw up the locking mechanism and possibly slightly screw up the connectors if you apply excessive force. I.E. with a set of small pliers it will likely be possible to straighten up any bent pins and whatnot).
@@Thesecret101-te1lm Well if the same connector was used for two different purposes, having dissimilar locking mechanisms would aid in not getting them mixed up with each other, after all there are voltage rails (12V?) on the AUI port, that probably would not do a video monitor any good.
@@paulstubbs7678 Good point. PC joysticks use the same connector, but I've never heard of mistakes. Maybe the plastic "shield" of a PC joystic DA15 male connector just collides with the AUI locking mechanism so it won't even go in?
I've got a bunch of old MRV's in prod in legacy env's. If it ain't broke..They refuse to die. I've got tons of the flat blue cables in bins somewhere, Cisco used to give them away.
Something beautiful and satisfying about creating a collection of networking equipment that all inter operates perfectly, and yet it has no real purpose :)
Thanks for the video, nice to see different terminal servers :) The popular terminal servers from DEC use RJ45 for serial connection in more recent products (e.g. DECserver 90M, in older products they used MMJ) an they have a different pinout than cisco as well. I had to build new cables for that devices...
Cisco Router as Terminalserver is definetly underrated! My favorite is the ISR 2911 with the HWIC-8A module. The cool thing is you can even do reverse SSH if you dont want telnet.
Not sure on the Cisco, but the MRV can also do SSH. SSH is more secure, and allows you to generate authentication cert pairs that can grant transparent pass through on the serial device side. So you ssh to the console switch, have transparent auth, and immediately presented with the console of the connected device. SSH secure auth, telnet basic pass through all encrypted on the ethernet. This works well with expect scripting the remote devices. For the Cisco on the MRV, try where 1 is the port port async 1 no dsr wait port async 1 no flowcontrol port async 1 no banner file port async 1 no autohangup port async 1 name router port async 1 max mirror connections 5
it’s amazing how long these cables / adapters / switches / routers work for. if these were made today, they’d probably break by the time their warranty ends. this was a time when (most) companies cared about their customers more than they cared about revenue.
Indeed. It's why Cisco has become such an ass at "erasing history". Once something is end-of-support, they delete just about everything about it from their systems... starting with the IOS images. Granted, with the speeds of modern networks, most things over a decade old are just too slow. But when you don't care about (or need) high speeds, these things just keep on kicking.
that audit code at 3:30 date lines up to around when southwest airlines shut down their terminal based maintenance software called wizrd. everything got shut down on that end and now it all goes through their new tracking software called maintinex which is ran on a custom version of IFS. so you possibly have some old airline equipment
Really love this content, minimal video-editing keeps a nice focus on the content itself, and this being pretty unique content also makes it a bit special.
When I used to work on Cisco equipment, I would do all my configs in a text editor then copy and paste the config into the device. That way if I didn't do a "wr t", or a "copy run start", I would have a back copy of the config.
I worked at a local ISP a few years ago. We still had tons of 2500's with the octopus cables, and we had them on an OOB circuit at every CO incase of an outage. It was super useful if you were doing a firmware update, because you could just console into any device from the office.
Thanks so much for showing terminal server use. I work in the electric utilities industry (not in IT though) and there is always a mish-mash of communications equipment used from the past 50+ years. I had heard of terminal servers, but never dug into the details. This was a great demonstration!
I have a raspberry pi zero with a USB COM port adapter serving a terminal server purpose. Its purpose is similar - so I can watch my OPNsense firewall reboot (always makes me nervous) and have recovery if I ever mess up a network config. That pi zero can be accessed via an ethernet hat, or via its wifi, connected to a secondary wireless network in case my ISP ever goes down. Those little USB->Serial COM port adapters are priceless in a network outage scenario. The pi zero is the perfect form factor to just shove in the network panel in my apartment.
I used to use a Cisco AS2511-RJ which was a 16 port version of the 2509 but instead of the breakout cables, it had (normal wired!) RJ45 connectors on the back.
Still have one in my lab today, in reasonably regular use. Have the green cables that are used here too which made me wonder about the pinout comments about the MRV.
You can make a "poor mans" terminal server using a low power device like a raspberry pi and a program called "conserver." Previously I used a pogoplug running debian linux, but recently i switched it over to a wyse 3040 running debian linux. I have a 7 port usb hub with a bunch of usb to serial cables connected. This morning, i used the last open port to connect the serial port on my dell kvm. (I blame/thank clabretro for this purchase. i picked it up off ebay after i seen his video on them.) I plan on upgrading to a much larger hub.
I used to work at a company that I'm fairly sure had the largest conserver deployment in the world and can definitely recommend it. Thousands of devices with an autogenerated configuration and barely ever even gave us hiccups. The ability to spy on connections while other people (or automation) uses the port is super useful.
Funny, I never used terminal servers as last-resort management console servers. I always only used them to connect serial leased-line modems between branches of control stations (water works, etc.). They had cheap phone cables between remote locations, and we used them to connect the SCADA systems via IP. Worked surprisingly well over miles of copper cable. The terminal servers had tons and tons and tons of serial modems connected to them.
My first thought when reading "terminal server" was a server for a bunch of terminals, not the other way round Also, if the octocable isn't long enough, you could use rj45 extension leads/gender changers, or just cut off the existing plugs and replace them with keystones like some sort of barbarian
I'd imagine most of these terminal servers would also work how you describe., where a serial connection initiates a network connection. Hardware-wise it's the same, just a software config difference.
thank you for reminding me that there were 2500 series routers that could do terminal services; I was thinking about getting an MRV for OOB management for my router/switch/ntp server/dns server/etc., but I have a soft spot for the 2500's as that hardware was what I learned network configuration on in high school, and just picked up a 2509 with a squid cable for $80 instead.
"could do" and "do well" are miles apart. As a console server, cisco's stuff is passable. For dialup termination, Cisco is the worst technology in human history - which is sad seeing how they bought telebit. (but they only wanted the "mica" DSP modem tech. they almost literally threw away the netblazer software - the best RAS tech ever... if you could power the serial ports, a 386/40 with 4MB of RAM booted from a 1.44MB 3.5" floppy could handle 192 sessions with ease.)
I've been on the hunt for a Cisco 2500 for my homelab for 2 years. So hard to find in Australia, and when they do come up the recyclers that list them on eBay want $$$$$. I just have a separate VLAN for management now where I can telnet into basically everything now anyway or access the GUIs but still... I yearn for the 2500
Oh man I haven't seen one of these since I was in highschool. I love your videos. You should do one on a cisco 5500 series next. They are boat anchors compared to the 6500 that replaced them but still awesome.
Many years ago our work databases at branch offices ran on MicroVAX hardware and we had a bunch of those AUI to Ethernet adapters in use. Also the “silver satin” flat serial cable to VT100 terminals. Wild stuff back then.
I never worked with the octopus cable but i did work with AUX to Eth port changers. they are a set it and forget it kind of thing and never saw one get removed. One thing about old Cisco 2500 and 2600 routers i've had a problem with was when the NVRAM won't save your config (i think the battery was bad and at the time I wouldn't take it apart to find out) Great video!
Isn't out-of-band (OOB) management fun? Are you thinking of getting a second half-height rack like your existing one, and dedicate it to the Cisco and other clab gear? That should allow the octal cable to reach. Although I wonder if you used CAT5/CAT6 couplers and a patch cable if that could extend the reach? Love the content. Keep it coming.
Terminal Servers are still extremely popular in embedded electronics labs. It's the only good way to connect to lots of embedded devices for development, testing and debugging that really scales.
When you find out there are RJ45 to RJ45 couplers, so you can take the end of the console cable and just extend it with a regular patch cable... I have a cat5 one in my bag, that I've had for 30 years, still works great when you need it.
One of the most beautiful videos. regarding that big connector, my company is in an area that was not covered by fiber connection until 2020. We had a connection via antenna (1 repeater us, 1 telecom italia our provider) of 1GB symmetrical with 16 reserved IP addresses. The antenna came from the roof with Ethernet cable going into a Cisco 1841. Attached to the serial board of the 1841 was a 2MB symmetric SHDSL modem that intervened when the antenna dropped, bringing the connection with all 16 static IPs over copper. The large connector was on the modem side. We decommissioned it in 2020 as they put fiber in all major areas. I live where the Olivetti headquarters is, those who are into retro-computing know what kind of company we are talking about, and fortunately in connectivity we have always been in good shape, the city of Ivrea is one of the first in Europe to have activated 5G
We use 3 Avocent ACS console servers in our labs to connect our 50+ pieces of routers and switches. We have a network directory with full of command icons (.lnk) so you just click and a putty terminal is started with the router orcswitch in the rack. As an admin I can sniff in the terminal, or even I can write in it, tonhelp them. There are also usernames and passwords so they cant reach each others devices during writing a test.. I cant live without it any more.
We had some 2500 series set up that way. To add security, years ago I ran the Ethernet lines through a hub to a spare Ethernet port on a linux server. We just ssh to the server then telnet to the console ports from there
You can get a patch panel with RJ45 keystones and extend the serial cables wherever you would like them to go. There is already a rollover in the octopus cable, so all of the rest of the cabling would be straight-through. This also would allow you to have more serial port devices than you have serial ports, and you'd only need to move around a patch cable to swap (I am assuming you would make half the patch panel be the terminal server connections and the other half be serial ports, and patch them together, but you can do whatever you want).
If I remember right from reading through a lot of information on these terminal servers (cisco still makes modules for it's modular routers,, you could definetly slot a HWIC-16A into your 2900 series), the aux port is special, because it supports hardware flowcontrol. That is probably why it was the only one that could successfully connect to the modem. And yes, hardware similar to these, is what I'm currently removing from the network at work, they served their time as terminal servers for remote backup managment, and are now being replaced or phased out.
As soon as I saw that 10BaseT to AUI adapter my mind went into rewind to 1990. At that time, it would have been 10Base2 - the coaxial version, with T connectors, terminators and the myriad of things that made it fragile. Also had the 10Base5 cables and transceivers with a AUI drop cable. There were so many products emerging, such as Token Ring and FDDI. I built an FDDI Based Network only to learn that 100BaseT had just been demonstrated. Happy days.
I remember one brand of networking equipment I had, I setup the switch, turned on the ports, turned on POE and enabled the 10Gbe ports, put them all in the same network etc. then saved it, all good, rebooted all good, but apparently you have to "verify" because after 30 days it just reboots and wipes all data. Gotta love these "security" features haha
I built something similar as a teenage apprentice that communicated with serial ports of scales. It’s still a product sold to industrial customers but of course managed by more experienced people. All with a hitachi H8 8-bit microcontroller. I miss doing this stuff. But not in retired on disability and i just watch RUclips videos about this stuff
Love all that older hardware. I used to work with a lot of the hardware you have shown. It's weird, but I do miss the sound of a modem dialing up from time to time.
You can get cables that connect to a Cisco console port that have a built in serial to USB adapter that you can plug in to a Raspberry Pi and run minicom on the Raspberry Pi. Of course if you have several things with console ports or if want to connect some VT220s of something like that I guess a terminal server would be handy.
You could set the modem to 56.7 K or 115.2 K to allow for data compression, if you hardware flow control is working and the port on the device it is connected to can handle the speed. For what you are doing It probably wouldn't matter.
Great video, Bougth a Cisco pix 515e and a Catalyst 2950 earlier this month The catalyst arrived a couple weeks ago and the Pix yesterday the pix had the cmos battery holder broken off will probably stick it with some electrical tape in the meanwhile and sometime learn soldering or take it to the local video game shop to ask if they could fix it.
I'd be more interested in seeing you put together a modern, good solution. Like setup a "software SIP modem server" (there are a few available). With that, one $100 8-port ATA would provide 8 dial-up lines. You could publish SIP credentials and let people buy their own ATAs and configure them to do dial-up to your modem server. You could buy an ATA with "FXO" ports and connect it up to a PSTN landline for old fashioned dial-in. Or buy a T1 PCI card and install in your SIP server.
Transport configures what protocol you're using. You can configure it to only use like telnet or ssh or whatever by entering for example transport input ssh. Transport output configures what protocol you're using when logged into the device to connect to another device. Transport output ssh only allows you to use ssh to connect to another device from what line you're logged into.
I tried to explain to my girlfriend why I’ve been watching videos on late 90’s to early 00’s enterprise networking equipment and… I have no idea but please keep them coming lol
no end in sight lol
I feel ya, those are always awkward conversations 😢
If she's "the one" then she should understand you without explanation.
Its where "it" all started to form. And it hasnt changed much. For example, auth protocols like PPP from the 90s are still used every day in modern fiber connections.
I love this channel :)
Right with ya
Working for an ISP in the 90's, we had dozens of 2511's handling inbound dialup PPP sessions, each with its own discrete rack modem. A call group (POP) might have a hundred or more modems. The core router at each POP was a Cisco AGS+, with ISDN being used for inter-POP links initially, later moving to Nx64k sync serial, then frame relay, then ATM. Dialup access moved to the 5200 (which had 60 discrete modem DSP chips in 2 rack units - the heat coming out was diabolical), then the 5300 (which could handle up to 480 calls, no longer using a DSP-per-caller, if I remember correctly).
We used the Cisco 5200 and 5300 as well - "Access Server" (so 'AS5200' and 'AS5300'). Both were 2U, and had 48 and 96 modems per card, respectively, with multiple cards able to run in each unit. 'MICA' and "Microcom' modems (trunked in over T1 lines), I think the MICA modems had more trouble with low-quality lines.
The Serial Port is another RUclips channel that dives into enterprise gear from this era. They rebuilt exactly what you described: a dial-in ISP, with modems going into a terminal server via PPP, then out to "the internet". It's great to learn a bit more history from them.
It was a great time to be working at an ISP! I loved my time doing the same.
Terminal servers still rock today So much hardware from storage to switches to power distribution stuff still needs serial port access. Especially when they fail. They were so expensive back then now they are so cheap. Thanks for the video
Long Live RS232! I use Moxa 16 and 32 port terminal servers to control TV's and other devices in commercial AV installs. Functions the same way - IP address + port#. Also use CAT6 to do all the runs. I could do a lot of it over IP, but RS232 always works! 99% of Commercial LED (and a fair number of consumer) TV's still come equipped with a serial port. (normally on a 1/8" TRS jack)
I used to work in digital signage - we didn't use the RS232 ports, but I did love the adapters with crazy 7 way 3.5mm jacks 😆
Dude, just this week I set up two RS485 busses in a factory. The old stuff never dies, if it works, if it ain't broke, don't fix it.
This is what i need now to calm down to get ready to sleep
Dude's got a soothing voice, I'll give you that! Usually when I'm ill, laid up in bed, I listen to Bob Ross. This channel might make a nice fill-in.
I can tell you, his voice and of course the antics, are very enjoyable while I have a lazy brunch on a day off
Thank you for pausing to explain the port mapping on Telnet to the physical serial ports on the devices and how things are connected. Really helps me grasp how things are stung together.
Nothing like an unexpected Clabretro drop after work on a Tuesday!
Wednesday?
Thursday here!
I love the custom cisco desaturated blue grounded ethernet connectors on the octopus cable, who else but cisco!
Appreciate your audio so much. No lip smack sounds like most you tubers. Loving this content!
thanks!
@@clabretro make a video of just an hour straight of lip smacking
If you're in it for fun, having a second rack opens up the natural if not necessary opportunity to build out the racks as independent units that then need to be networked together and internally self-sufficient for things like these terminal servers
At work we're fortunate enough to have Avocent 8000 series concentrators. 48 ports, HTML5 interface, and auto detecting cable settings. Love them so much. They're absolutely rock solid. :D
Wow!! just wow! took me back 20 years to when I was studying for my cisco exams! the octopus cable setup using 2 C2509's was such a time saver!! thank you for bringing this back!!
That big connector is a v35 serial connector
Classic reverse telnet configuration. The 2500s are a throw back, they were the first router I touched in a networking vocational class I took growing up. Back at my first job I was supporting a retailer that had modems in each router for backup and OOB management, we had to use HyperTerminal to dial into the router for troubleshooting when the connection was down. Crazy thing that you can do with it is use them with a dial backup configuration if you setup a dialer interface. I always found a router serving an entire lan with a 56K modem that it auto dials a crazy idea as I only though of dialup internet before from the point of a single host calling out.
We used to use these as emergency access paths back when I worked at an ISP
If routing stuffed up, we wouldn't exactly telnet into to a console. So we had a modem connected to a terminal server, connected to our core routers and the edge to our management network
So if we stuffed something up, we didn't need remote hands to reboot the routers (which only worked if it was a config change obviously) we just dialled up a modem, hit the terminal server and jumped into what ever router my mentor broke :D
(Trust me, I broke my fair share of stuff too when I was learning)
Honestly man, these videos are just great, always good to watch
thank you!
the config works that way because you can set a timeout to reboot, which means when sending big/important/complex changes over you can schedule the router to reboot in X mins if not cancelled. so if you send over some config changes that break connectivity to the router or anything else the changes will be reverted automatically by the timeout reboot. if everything is working, just cancel the reboot. saved my butt more than once.
Only works if everything you are configuring does the same thing.
Never knew you could do "wr". So simple. I was taught "copy run start" in my CCNA but both work on my modern Cisco router
It depends on IOS version now. Sometimes it works and sometimes it doesn't. I don't remember which version or what the difference was, but I remember working on Cisco 55A2s where commands weren't immediately active unless you ended configuration, and "copy run start" threw an error lol.
Finally a clabretro video that didn't have me shopping on ebay! We use Cisco at work. We use the Aux port on the routers in remote stations to connect to the console of a server or other router. I have several of those same brand AUI adapters that I got from work. They are very nicely made.
So you have a POTS service to a dial up modem connected to the terminal server, and if conectivity goes down you dial into the terminal server as OOB?
Oh, so I'm not the only one who call the "CAB-OCTAL-ASYNC - Cisco 72-0845-01" the "Octopus cable"
No, and I used them as late as 2013 for OOB access to our core network and routers in case of emergencies. I had to use it twice in the 5 years I had it there, using a 10Mpbs leased line from the DC when all 3 of our unlink went down and I wasn't on any of our peer networks. Fun times.
Cables with the same idea, i.e. one multi pin connector to several connectors with fewer pines, are used for stage lighting, and those are called whips :) (the stage lighting multi channel connector is called socapex)
@@Thesecret101-te1lm Yeah, those are neat to.
@@Thesecret101-te1lmwhips, i never heard that in the uk. I use fan-in, fan-out, breakout or tails set. At least for soca->15A/16A.
The holy grail of terminal servers from the 2500 series is probably the as2511-rj which has 16x RJ45 serial ports built-in for the rollover cables.
In my experience (10+ years ago), the 2500-series were rapidly going away and we mostly used the 2800-series with 4x octopus cables for lab use.
Notably, there are HWIC-8A and HWIC-16A that also take octopus cables (CAB-HD8-ASYNC) which I think are a different connector.
Those HWIC-8/16A are really sweet, I have been eyeing those as well!
What's funny is you mentioned Cisco being the 'standard' on serial ports, they wire their stuff differently. I work with SANs and when you have to connect to a controller via serial we always have to ask to make sure they aren't using a cisco serial console cable. ;)
Cisco is pretty much the standard across all networking consoles across all brands, but yeah storage and other categories decided to be different, for no apparent advantage.
The worst I know of is plugging a "standard" Cisco console cable into an APC UPS resulting in an instant power off of the UPS and everything connected.
@@incandescentwithrage Glad I am not the only one who made that mistake, my go to story about how old APC UPSs aren't so Uninterruptable. BTW it wasn't just Cisco cables it happens with regular Null Modem cables I had to order the specific APC cable for it to work.
When running a pair of 2501, it was useful to connect the aux on each to the console of the other. This allowed using the partner to do disruptive upgrades, etc.
I used this on a pair of 2800s we deployed for an event, and thought I was pretty smart for figuring it out until I found out it's a pretty common thing that's been used on pairs of routers for ages.
The rollover cable literally flips pin 1 -> 8, 2 -> 7, 3 -> 6 and so on... It rolls the cable over. That's the kind of cable needed for the MRV around 4m10s.
Recently dug up an identical AUI to RJ-45 adapter to show a friend, which is why I clicked the video... Now seeing many flashbacks to the start of my first career.
Those cables aren't to special if you have the old (blue, not molded) Cisco console cables, they're the same.
That's exactly what the blue cables do. The black cables were straight-through for connecting modems to the AUX port.
Also: Unless cisco has some special hardware that can flip the pins internally, it wouldn't work to connect two octopus RJ45 connectors to each other with a straight RJ45 female-female adapter, or more importantly it wouldn't work connecting the AUX port of two Cisco routers to each other, or for that sake the console port to each other.
I.E. even when exclusively using cisco equipment you would need flipped and straight cables.
Suggestion to @clabretro: Either make a simple adapter that breaks out each RJ45 pin to a banana jack or just something that you can put alligator clips on, to use with a multimeter, or get one of those RS232 debug thingies with a bunch of LEDs and whatnot, in order to find out what is going on when a serial connection don't work.
Btw, flipped and non-flipped cables have been the bane of existence for any type of consumer electronics equipment that uses the same connector for signals in both directions, like for example a tape recorder. The SCART connectors (common on European TVs and whatnot) mostly solved this by defining the pins as in or out rather than things like record and play). However the older DIN connectors had pins defined as record and pins defined as playback, and in some cases you had to use crossover cables to copy between two tape recorders. In other cases you didn't need that, as some tape recorders only connected an output signal to the play pins while in playback, and otherwise used those pins as an extra recording input (with different signal levels - line level recording on the playback pins and microphone level recording on the recording pins)...
I had a 6 line BBS back in the mid 90's and used something call a boca board. it was an IDE card that had a fat cable that hooked up to a 16 port RJ45 breakout box and had 16 RJ45 to 25pin serial ports. it worked like a charm, and i have no idea how i did all that at 16
Completely enthralled, love it. Old equipment is so good.
The big connector is v35. It was typically used to connect CSU/DSUs for 56k or T1’s
I haven't seen that name in a long time. Back around 2008 we were doing network upgrades after a large bank acquired a smaller one. Found an abandoned closet full of terminal servers. Apparently many years prior they were used for a different application, to link banker's dumb terminals back to the main office.
Blockbuster video also used terminal servers. Each store ran a AlpahServer DS10 in the back and the front end ran a PC that booted DOS from a floppy disk. They ran this setup until they went out of business. Must have cost them a fortune to maintain.
Nit pick: IT was V35, but the V35 standard expired and thus it's "former v35".
Anecdote: A friend had decided to never ever have to have anything to do with V35 in his IT career :D
MAU - Media Attachment Unit, it connects the port, the AUI to the actual network cable, the media.
In the beginning, ethernet cable was a quite thick and almost inflexible cable, you didn't run this to your equipment, it stayed up in the suspended ceiling, or under a raised floor. You used an attachment box, or tap that 'spiked into' that cable, this tap box was then connected to your computer by a way friendlier flexible cable to the AUI port of your computer.
Later on they came up with 'Thinnet' that used much thinner coax that was convenient to bring to the back or your computer, so we had these adapter boxes simular to yours, but with BNC connectors on them. Then came 10baseT with the modern RJ45 connectors, and the adapters you have.
And in particular with the transceiver/MAU a bit away from the device it was of course just a regular DA15 connector and thus way less risk och breaking the connector if you pull on it.
This type of AUI cable can be used with transcievers/MAUs used in this video too!
(Not 100% sure but I think that the locking mechanism is intentionally weaker than the regular d-sub screws just so that you "only" screw up the locking mechanism and possibly slightly screw up the connectors if you apply excessive force. I.E. with a set of small pliers it will likely be possible to straighten up any bent pins and whatnot).
@@Thesecret101-te1lm Well if the same connector was used for two different purposes, having dissimilar locking mechanisms would aid in not getting them mixed up with each other, after all there are voltage rails (12V?) on the AUI port, that probably would not do a video monitor any good.
@@paulstubbs7678 Good point. PC joysticks use the same connector, but I've never heard of mistakes. Maybe the plastic "shield" of a PC joystic DA15 male connector just collides with the AUI locking mechanism so it won't even go in?
I've got a bunch of old MRV's in prod in legacy env's. If it ain't broke..They refuse to die. I've got tons of the flat blue cables in bins somewhere, Cisco used to give them away.
Something beautiful and satisfying about creating a collection of networking equipment that all inter operates perfectly, and yet it has no real purpose :)
Thanks for the video, nice to see different terminal servers :) The popular terminal servers from DEC use RJ45 for serial connection in more recent products (e.g. DECserver 90M, in older products they used MMJ) an they have a different pinout than cisco as well. I had to build new cables for that devices...
Cisco Router as Terminalserver is definetly underrated! My favorite is the ISR 2911 with the HWIC-8A module. The cool thing is you can even do reverse SSH if you dont want telnet.
My favorite is a 2600xm with NM-32A
You can attach that v.35 cable to an Adtran.
No idea why but I love this stuff. Seeing the gear that ran early internet is absolutely fascinating.
I used a bunch of old DECnet terminal servers for three factories full of serial terminals. I remember those aui dongles too
Not sure on the Cisco, but the MRV can also do SSH. SSH is more secure, and allows you to generate authentication cert pairs that can grant transparent pass through on the serial device side.
So you ssh to the console switch, have transparent auth, and immediately presented with the console of the connected device. SSH secure auth, telnet basic pass through all encrypted on the ethernet.
This works well with expect scripting the remote devices.
For the Cisco on the MRV, try where 1 is the port
port async 1 no dsr wait
port async 1 no flowcontrol
port async 1 no banner file
port async 1 no autohangup
port async 1 name router
port async 1 max mirror connections 5
definitely! haven't gotten around to trying that out yet
it’s amazing how long these cables / adapters / switches / routers work for. if these were made today, they’d probably break by the time their warranty ends. this was a time when (most) companies cared about their customers more than they cared about revenue.
Indeed. It's why Cisco has become such an ass at "erasing history". Once something is end-of-support, they delete just about everything about it from their systems... starting with the IOS images. Granted, with the speeds of modern networks, most things over a decade old are just too slow. But when you don't care about (or need) high speeds, these things just keep on kicking.
As a Cisco network engineer I enjoy these videos very much.
that audit code at 3:30 date lines up to around when southwest airlines shut down their terminal based maintenance software called wizrd. everything got shut down on that end and now it all goes through their new tracking software called maintinex which is ran on a custom version of IFS. so you possibly have some old airline equipment
Really love this content, minimal video-editing keeps a nice focus on the content itself, and this being pretty unique content also makes it a bit special.
thanks!
Outgrowing your server rack? A 37U rack on casters rolls through most doorways.
When I used to work on Cisco equipment, I would do all my configs in a text editor then copy and paste the config into the device. That way if I didn't do a "wr t", or a "copy run start", I would have a back copy of the config.
I worked at a local ISP a few years ago. We still had tons of 2500's with the octopus cables, and we had them on an OOB circuit at every CO incase of an outage. It was super useful if you were doing a firmware update, because you could just console into any device from the office.
ah interesting!
9:34 is a V.35 connector.
Thanks so much for showing terminal server use. I work in the electric utilities industry (not in IT though) and there is always a mish-mash of communications equipment used from the past 50+ years. I had heard of terminal servers, but never dug into the details. This was a great demonstration!
Glad you enjoyed it!
Man, never disappointing with these vids!
when i got my ccna home lab this exact “octopus” cable and 2509.. thanks for this video - now i FINALLY know what i can do to set it up
Back in the day, we used to have Cyclades console/terminal servers. I miss'm, they were pretty cool!
Looking forward to the rack expansion!
tinkering with my own home lab these videos are always fun to watch
Awesome stuff as usual, so interesting to see how all this old gear works having only first handled rack servers in 2018.
terminal servers
serminal tervers
@@owenvogelgesang7314 servinal termers
@@owenvogelgesang7314servinal termers
Semen terror
@@xp7575 💀
Huh, quite a coincidence. I was just looking up how to do this with a modern Cisco switch. Yes, you can still do it.
I have a raspberry pi zero with a USB COM port adapter serving a terminal server purpose. Its purpose is similar - so I can watch my OPNsense firewall reboot (always makes me nervous) and have recovery if I ever mess up a network config. That pi zero can be accessed via an ethernet hat, or via its wifi, connected to a secondary wireless network in case my ISP ever goes down. Those little USB->Serial COM port adapters are priceless in a network outage scenario. The pi zero is the perfect form factor to just shove in the network panel in my apartment.
Old external CSU/DSUs (like the adtran) used those big HSSI(?) cables. Back in the 90s we used them for frame relay connections.
I sure hope this video is about terminal servers.
I used to use a Cisco AS2511-RJ which was a 16 port version of the 2509 but instead of the breakout cables, it had (normal wired!) RJ45 connectors on the back.
Still have one in my lab today, in reasonably regular use. Have the green cables that are used here too which made me wonder about the pinout comments about the MRV.
You can make a "poor mans" terminal server using a low power device like a raspberry pi and a program called "conserver."
Previously I used a pogoplug running debian linux, but recently i switched it over to a wyse 3040 running debian linux. I have a 7 port usb hub with a bunch of usb to serial cables connected. This morning, i used the last open port to connect the serial port on my dell kvm. (I blame/thank clabretro for this purchase. i picked it up off ebay after i seen his video on them.) I plan on upgrading to a much larger hub.
I used to work at a company that I'm fairly sure had the largest conserver deployment in the world and can definitely recommend it. Thousands of devices with an autogenerated configuration and barely ever even gave us hiccups. The ability to spy on connections while other people (or automation) uses the port is super useful.
Funny, I never used terminal servers as last-resort management console servers. I always only used them to connect serial leased-line modems between branches of control stations (water works, etc.). They had cheap phone cables between remote locations, and we used them to connect the SCADA systems via IP. Worked surprisingly well over miles of copper cable. The terminal servers had tons and tons and tons of serial modems connected to them.
I have watched your videos for a while now and I fear you have fallen into the rabbit hole and will never find a way out again LOL
once the analog lines started showing up I was toast
@@clabretro gluten for punishment LOL
My first thought when reading "terminal server" was a server for a bunch of terminals, not the other way round
Also, if the octocable isn't long enough, you could use rj45 extension leads/gender changers, or just cut off the existing plugs and replace them with keystones like some sort of barbarian
I'd imagine most of these terminal servers would also work how you describe., where a serial connection initiates a network connection. Hardware-wise it's the same, just a software config difference.
thank you for reminding me that there were 2500 series routers that could do terminal services; I was thinking about getting an MRV for OOB management for my router/switch/ntp server/dns server/etc., but I have a soft spot for the 2500's as that hardware was what I learned network configuration on in high school, and just picked up a 2509 with a squid cable for $80 instead.
"could do" and "do well" are miles apart. As a console server, cisco's stuff is passable. For dialup termination, Cisco is the worst technology in human history - which is sad seeing how they bought telebit. (but they only wanted the "mica" DSP modem tech. they almost literally threw away the netblazer software - the best RAS tech ever... if you could power the serial ports, a 386/40 with 4MB of RAM booted from a 1.44MB 3.5" floppy could handle 192 sessions with ease.)
I've been on the hunt for a Cisco 2500 for my homelab for 2 years. So hard to find in Australia, and when they do come up the recyclers that list them on eBay want $$$$$. I just have a separate VLAN for management now where I can telnet into basically everything now anyway or access the GUIs but still... I yearn for the 2500
oof. I'd ship you that 2501 but I'm guessing you want one with an async port?
@@clabretro Thanks but It would probably cost a kidney just to send it to me down under!
Oh man I haven't seen one of these since I was in highschool. I love your videos. You should do one on a cisco 5500 series next. They are boat anchors compared to the 6500 that replaced them but still awesome.
Many years ago our work databases at branch offices ran on MicroVAX hardware and we had a bunch of those AUI to Ethernet adapters in use.
Also the “silver satin” flat serial cable to VT100 terminals. Wild stuff back then.
I never worked with the octopus cable but i did work with AUX to Eth port changers. they are a set it and forget it kind of thing and never saw one get removed. One thing about old Cisco 2500 and 2600 routers i've had a problem with was when the NVRAM won't save your config (i think the battery was bad and at the time I wouldn't take it apart to find out) Great video!
Isn't out-of-band (OOB) management fun? Are you thinking of getting a second half-height rack like your existing one, and dedicate it to the Cisco and other clab gear? That should allow the octal cable to reach. Although I wonder if you used CAT5/CAT6 couplers and a patch cable if that could extend the reach? Love the content. Keep it coming.
OOB Management (out of band). Also, you put an RJ45 pass through patch panel in so you can extend as far as you want
Terminal Servers are still extremely popular in embedded electronics labs. It's the only good way to connect to lots of embedded devices for development, testing and debugging that really scales.
When you find out there are RJ45 to RJ45 couplers, so you can take the end of the console cable and just extend it with a regular patch cable... I have a cat5 one in my bag, that I've had for 30 years, still works great when you need it.
Love the terminal server action, those cables look great and there’s a modem involved 😀👍
oh well our nightmare in substations! another great video!
One of the most beautiful videos. regarding that big connector, my company is in an area that was not covered by fiber connection until 2020. We had a connection via antenna (1 repeater us, 1 telecom italia our provider) of 1GB symmetrical with 16 reserved IP addresses. The antenna came from the roof with Ethernet cable going into a Cisco 1841. Attached to the serial board of the 1841 was a 2MB symmetric SHDSL modem that intervened when the antenna dropped, bringing the connection with all 16 static IPs over copper. The large connector was on the modem side. We decommissioned it in 2020 as they put fiber in all major areas. I live where the Olivetti headquarters is, those who are into retro-computing know what kind of company we are talking about, and fortunately in connectivity we have always been in good shape, the city of Ivrea is one of the first in Europe to have activated 5G
Ha, amazing!
Hunny, wake up Clabretro dropped a new video
love your channel. always pumping out something interesting!
thanks!
Wow this MRV device is incredibly useful!!!
You seem like a guy that needs to experience 10base5. :D
😆
We use 3 Avocent ACS console servers in our labs to connect our 50+ pieces of routers and switches. We have a network directory with full of command icons (.lnk) so you just click and a putty terminal is started with the router orcswitch in the rack. As an admin I can sniff in the terminal, or even I can write in it, tonhelp them. There are also usernames and passwords so they cant reach each others devices during writing a test.. I cant live without it any more.
We had some 2500 series set up that way. To add security, years ago I ran the Ethernet lines through a hub to a spare Ethernet port on a linux server. We just ssh to the server then telnet to the console ports from there
You can get a patch panel with RJ45 keystones and extend the serial cables wherever you would like them to go. There is already a rollover in the octopus cable, so all of the rest of the cabling would be straight-through. This also would allow you to have more serial port devices than you have serial ports, and you'd only need to move around a patch cable to swap (I am assuming you would make half the patch panel be the terminal server connections and the other half be serial ports, and patch them together, but you can do whatever you want).
It’s always a good day when you upload! ❤
If I remember right from reading through a lot of information on these terminal servers (cisco still makes modules for it's modular routers,, you could definetly slot a HWIC-16A into your 2900 series), the aux port is special, because it supports hardware flowcontrol. That is probably why it was the only one that could successfully connect to the modem.
And yes, hardware similar to these, is what I'm currently removing from the network at work, they served their time as terminal servers for remote backup managment, and are now being replaced or phased out.
either a Cisco or eBay sponsorship must be in the realm of possibility at this rate 🤣
As soon as I saw that 10BaseT to AUI adapter my mind went into rewind to 1990. At that time, it would have been 10Base2 - the coaxial version, with T connectors, terminators and the myriad of things that made it fragile. Also had the 10Base5 cables and transceivers with a AUI drop cable. There were so many products emerging, such as Token Ring and FDDI. I built an FDDI Based Network only to learn that 100BaseT had just been demonstrated. Happy days.
I remember one brand of networking equipment I had, I setup the switch, turned on the ports, turned on POE and enabled the 10Gbe ports, put them all in the same network etc. then saved it, all good, rebooted all good, but apparently you have to "verify" because after 30 days it just reboots and wipes all data. Gotta love these "security" features haha
oof haha
I built something similar as a teenage apprentice that communicated with serial ports of scales. It’s still a product sold to industrial customers but of course managed by more experienced people. All with a hitachi H8 8-bit microcontroller. I miss doing this stuff. But not in retired on disability and i just watch RUclips videos about this stuff
You could call it a Hydra cable too, I'm sure!
Love all that older hardware. I used to work with a lot of the hardware you have shown. It's weird, but I do miss the sound of a modem dialing up from time to time.
I'd call it an octo-whip 😎
You can get cables that connect to a Cisco console port that have a built in serial to USB adapter that you can plug in to a Raspberry Pi and run minicom on the Raspberry Pi. Of course if you have several things with console ports or if want to connect some VT220s of something like that I guess a terminal server would be handy.
When i did my CNNA , I used those AUI Converters , those very same ones as in the video. Especialy for the old Cisco Kit that had no Ethernet.
It's part of every network engineer's experience to forget to send the WR command
I absolutely love your channel brother! Please keep up the good work.😊
thanks!
You could set the modem to 56.7 K or 115.2 K to allow for data compression, if you hardware flow control is working and the port on the device it is connected to can handle the speed. For what you are doing It probably wouldn't matter.
Great video, Bougth a Cisco pix 515e and a Catalyst 2950 earlier this month The catalyst arrived a couple weeks ago and the Pix yesterday the pix had the cmos battery holder broken off will probably stick it with some electrical tape in the meanwhile and sometime learn soldering or take it to the local video game shop to ask if they could fix it.
I'd be more interested in seeing you put together a modern, good solution. Like setup a "software SIP modem server" (there are a few available). With that, one $100 8-port ATA would provide 8 dial-up lines. You could publish SIP credentials and let people buy their own ATAs and configure them to do dial-up to your modem server. You could buy an ATA with "FXO" ports and connect it up to a PSTN landline for old fashioned dial-in. Or buy a T1 PCI card and install in your SIP server.
there is a ton of routers and switches where you configure the running-config and if you want to keep that config you have to copy running to startup.
Networking just because, love it!
oh yeah
8P8C, and the signal levels are the same as RS-232.
Transport configures what protocol you're using. You can configure it to only use like telnet or ssh or whatever by entering for example transport input ssh.
Transport output configures what protocol you're using when logged into the device to connect to another device. Transport output ssh only allows you to use ssh to connect to another device from what line you're logged into.