2811 router fails, configure replacement remotely

Unanswered Question
Apr 21st, 2008

Is there any way to access a 2811 router remotley to copy an existing config, or boot to a flash card with an existing config?

For example if a branch router fails, can you have someone rack the new router and boot to a flash card with an existing config to get back up quickly?

Or have some out of band management that would allow a remote person to do it?

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Overall Rating: 5 (5 ratings)
lamav Mon, 04/21/2008 - 17:03

Wilson, we gotta stop meeting like this...lol

The 2800 Series routers have a single, external compact Flash memory. This is the only Flash memory for the system and should never be removed during router operation.

The IOS, configuration files, and other files required for router operation are stored in Flash memory. Also, Flash memory allows software upgrades to be downloaded over the WAN or LAN link to be stored on this onboard Flash memory.

You can use the USB Flash memory to load IOS images but only if the rommon version is 12.4(13r) or later. Unfortunately, you cannot boot a configuration file from USB Flash.

All this having been said, I have been in the situation you've mentioned a lot of times, and depending on the onsite tech's knowledge base and experience, I either had an easy time loading a config or a miserable, tedious time that made me feel like stabbing myself in the eye -- repeatedly.

You can get pretty creative, but this is what I would normally do. Not altogether too elegant, but it did the trick.

1.) Always have a saved config file stored on your TFTP server or locally on your drive in the first place.

2.) Ask the onsite tech to rack mount the router, jack into the console port and configure 1 WAN interface so you can telnet to the router and apply the config yourself. Or do a copy tftp start and download the file through the network.

-- OR --

Email the config file to the tech and have him/her copy and paste it into the router, minus the aaa configs, if they're being used.

3.) If OOB access is provided, then use that, of course, if need be.

I don't know if this is the information you're looking for, but this is how I would handle it.



wilson_1234_2 Mon, 04/21/2008 - 18:17

Thanks again Victor,

Yes, I am here all the time getting great info from you guys.

I don't know what it is, but I cannot read the documents and get as much as whne I ask a specific question and someone much more experienced than myself answers.

I was looking for a one step approach that someone with extremely limited capability could do, like connect cables, plug in the flash or usb, boot and I am back up

But you probably would have already been doing that if you could, so thanks a ton for the info.

lamav Mon, 04/21/2008 - 18:32


I was looking for a one step approach that someone with extremely limited capability could do, like connect cables, plug in the flash or usb, boot and I am back up

Your expectation is reasonable indeed. But to my knowledge, and according to Cisco's literature on the 2800, it cannot boot off of a configuration file that resides in the Flash.

Although I do have experience, there are others on here who have tons of experience and expertise, too. So, please stick around and see if anyone offers a different approach that migh be more suitable for you.

Thanks again for your rating.


Richard Burts Tue, 04/22/2008 - 03:37


There is an alternative which will do pretty much what Richard wants. The boot config command allows you to specify a config file to use in the boot process and includes the ability to boot from a config file in flash. I tested this on an 1841 a while back. It worked fine and I believe that it will also work on 2800 routers. This link has more information about the command:




lamav Tue, 04/22/2008 - 05:43


Thanks, Rick.

I was thinking along those lines, too, but Cisco's literature for the 2800 (FAQ) says that you can't boot from a config file on the USB removable Flash.

Q. Can I boot a configuration file from USB flash?

A. No. Booting a configuration file from USB flash is not supported.

But, even if with some maneuvering that boot command does work, the onsite tech would still need to insert the Flash card into the new router, jack-in to the router's console port with a laptop, and then enter the boot config command, and then reboot the router. So, still pretty easy, as were the other choices, but not exactly what Wilson was envisioning.



Richard Burts Tue, 04/22/2008 - 07:22


The original post asked if there were a way to boot a router with a config file from flash. My response is that this is possible. Richard would be the one to tell us the details of how he wants it to work. But based on his description in the original post I would see it working this way: change the router config so that the config file is maintained in flash rather than in NVRAM. If the branch router dies, rack the new replacement router, transfer the flash card from the old router to the replacement router, boot the new router and have the same config now run on the replacement router.

[edit] in reading through the thread again a slightly different perspective occurred to me. Depending on whether the replacement router is stored at the branch ready to be used or is to shipped to the branch when the failure occurs, if the router is to be shipped to the branch, it would be quite easy to take a backup copy of the config and copy to flash, put the boot config statement in before shipment to the branch office, and then all the branch person has to do is to rack the router, connect network cables, and power up.



lamav Tue, 04/22/2008 - 08:21


You don't need to perseverate over minutia. I knew you wouldn't just let it go...

Wilson posed a scenario to us: router dies at a remote site...how easy will it be to configure the replacement remotely? That's it. Everything else is conjecture.

From his posts it is obvious that he wants a "one step" approach. You haven't offered one. They all require some level of involvement with either entering boot commands in a router using a laptop or copying a file to flash, or something to that effect.

And, as I mentioned before, Cisco's website says that one cannot boot the 2800 router from the USB removable flash.

I'm moving on...have a nice day.



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