2621 Terminal Server with NM-32A module - Can export configs?

[juandcc2014]

Hello, everyone.

I have been recently getting into networking and I have lots of network device to manage. I was considering a switch connected to all management ports of each network device, but also thought of using a terminal server like the 2621 router with an NM-32A module. 

Besides remote access, the goal is to be able to backup the configurations of each device to another device. This is possible via a management network on a switch, but I’m wondering if it’s possible by using the 2621 terminal server. For example, my computer is connected to the Ethernet or Serial port of the terminal server and I want to backup all the network device connected via NM-32A into my computer. Is that possible?

[Jens Albrecht · Accepted solution]

Technically this is possible as Cisco devices in general support xmodem: and ymodem: as source and destination for the copy command. This is typically used as a last resort for devices stuck in rommon mode if there is no other way to copy a new IOS to make the device work again. Hence these protocols need to be supported and theoretically you could do a "copy running-config xmodem:" to backup your devices. However, this is really tedious and slow, especially for larger amounts of devices.

Therefore, I would never consider to use the console cable for the backup of running devices.
Instead simply set up a TFTP or (S)FTP server on your PC or any other server/nas and use it to backup all devices.
You need it anyway to backup and update the software of your devices as you do not want to do this over the console connection for sure.

HTH!

[Leo Laohoo · Accepted solution]

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@juandcc2014 wrote:
the goal is to be able to backup the configurations of each device to another device.

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Nobody, outside of a teaching environment/lab, does this any more. 

Backup the config to an outside destination, using TFTP/FTP/SFTP.  Backup only NEW config changes as well (and not go "blindly" backing up the config when no changes were made). 

[Jens Albrecht]

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@Leo Laohoo wrote:

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@Jens Albrecht wrote:
the goal is to be able to backup the configurations of each device to another device.

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@Leo Laohoo Just want to point out that it was not me writing this.

[Leo Laohoo]

Oops.  Edited.

[Joseph W. Doherty]

BTW, as an alternative to using something like XMODEM (or its better alternatives, XMODEM-1K, YMODEM, ZMODEM, if supported), usually terminal emulators have a capture to disk feature.  I.e. set term len 0, enable capture, show config, disable capture and reset term length.

The forgoing can often also be used via a on-net, telnet kind of app too.  (I've done such, quite often.)

Time to get a download, of course, depends on size of config, which might not be too massive, and bandwidth.  Compared to typical LAN speeds, serial console will appear to crawl at 9.6 Kbps, but, again for non massive configs, at 115.2 Kbps, might be acceptable.

Laugh, when I started in IT, as a programmer, editing programs usually larger than config files, remote access was 300 bps, and in office access was 1.2 Kbps.  The CLI typing options, still available today, were very useful to speed up working at such low bandwidth rates.

[Joseph W. Doherty · Accepted solution]

Is that possible?

Yes.

Should you, though?

Probably not!!!

@Jens Albrecht has given some of the excellent reasons why not, but there are others too.  Likely why @Leo Laohoo notes it's generally not done except in a few special cases.

Usually, some NMS or dedicated app is setup to capture device configs.

Also, believe there's much a Cisco device can do, itself, to insure there's an external backup of its config, whether perhaps using archive commands or building your own EEM scrip.

Regardless all that, is it worthwhile to have the kind of console access you're considering?

Very much!  But, you're proposing to use a rather old EoL 2621 and you're aware of distance limitations of RS232?

You also mentioned using management ports.  You can, but personally, haven't usually used such as "secure" management was usually done across the "normal" network.  (Technically, probably not as "good" as a separate equipment management network, but often "good enough" especially considering costs.). However, it's really nice to have out-of-band console access.  (Another "luxury" I seldom had.  Again, this to reduce costs, and in the grand scheme, and MTBFs, often is a luxury.)