Router ignores SDM default config

Answered Question
Feb 19th, 2007

We have recently purchased a series of 2800 series routers. They all came with SDM preinstalled. However, two of them choose to completely ignore the sdm default configuration file (sdmconfig-2801.cfg). SDM works OK, as long as I configure the routers by hand for remote HTTP/HTTPS access.

The routers seem identical in every way - but all the others load the sdm config file (with the banner, the username/password, the http access class, and so on).

Is there any hidden setting that determines whether a router loads that configuration file or not?

Thank you,

I have this problem too.
0 votes
Correct Answer by Richard Burts about 9 years 7 months ago

Bogdan

On the routers that normally boot and have SDM, if you erase startup and reload, do they still come up with SDM?

HTH

Rick

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)
Loading.
Richard Burts Mon, 02/19/2007 - 09:07

Bogdan

When you boot these routers do they go through the startup dialog?

Probably the most common cause of symptoms such as you describe is the setting of the config register. When you do show version the content of the config register will be displayed at the bottom of the output. If the next to last digit is 4 (most commonly 0x2142) then that setting tells the router to ignore the startup config when it boots.

If your config register is set to 0x2142 then change it to 0x2102 and see if that does not fix your problem with these routers.

HTH

Rick

bogdan.sass Mon, 02/19/2007 - 09:22

First of all, thank you for the quick reply!

I already checked the config register - it's 0x2102 on all the routers. The routers that load the SDM config file start by displaying the default banner ("SDM has been installed on this router [...]"), and asking for a username/password combination. The other two, however, behave just like routers without SDM installed - they ask me if I want to enter setup mode or not.

Richard Burts Mon, 02/19/2007 - 09:34

Bogdan

It would be very interesting to know what is in startup config for the routers that are not starting with SDM. Can you post the output of show startup-config from one of these routers?

It might also be helpful to know if you purchased these routers from Cisco or from someone else. I wonder if you purchased them from someone else whether they may have altered the config to bypass SDM (which I typically do when I configure a router for its first time).

HTH

Rick

bogdan.sass Mon, 02/19/2007 - 12:41

The routers that start up without SDM have empty startup configs:

Router#sh start

startup-config is not present

The other routers use the default SDM config:

yourname#sh start

Using 2460 out of 196600 bytes

!

version 12.4

service timestamps debug datetime msec

service timestamps log datetime msec

no service password-encryption

!

hostname yourname

[--snipped--]

All the routers are new, purchased from a Cisco distributor (and again, they should all be identical. In theory, at least :) ).

Could you please tell me what you do in order to configure the router to bypass SDM? That might provide some useful hints...

Richard Burts Mon, 02/19/2007 - 12:49

Bogdan

If purchased from a Cisco distributor they SHOULD be identical, but obviously they are not identical.

I remove from the config various things that are put there by SDM including the self signed certificate, the username, the login local, the privilege level 15 on the vty, the http server and secure http server. I also delete the SDM files that are in flash.

If you want SDM, I wonder if it would be enough to copy sdmconfig-2801.cfg from flash to startup-config.

HTH

Rick

bogdan.sass Mon, 02/19/2007 - 13:13

Copying that config to startup is a great idea, and it would probably work - but there is a small... glitch. We are a Cisco Networking Academy, and those routers are part of our lab bundle. And the first two commands any (good :) ) student issues on a router are "erase startup / reload". Which means that config will not last for long...

Since they are lab routers, I can provide any command output from them (no confidential data there :) ). But I have no idea what I could post here that might be relevant to the issue...

Correct Answer
Richard Burts Mon, 02/19/2007 - 14:03

Bogdan

On the routers that normally boot and have SDM, if you erase startup and reload, do they still come up with SDM?

HTH

Rick

bogdan.sass Mon, 02/19/2007 - 14:16

Yes - when they boot, they use the SDM configuration file (sdmconfig-2801.cfg) as their default startup config. The other two routers simply ignore it (although they have it in flash).

[Later edit - I just tried it again, and I was DEFINITELY wrong there! If I erase the startup config, they just boot normally, and try to go into setup mode.

So you were right all along - the router doesn't actually load the cfg from flash. It has that information factory loaded into its startup config. If I wanted to go into "normal" boot mode, I only had to erase the startup config. If I want the SDM config, I can copy the cfg file to startup config. ]

Thank you very much for all your help!!

Richard Burts Mon, 02/19/2007 - 15:31

Bogdan

Thank you for marking the problem as fixed (and thanks for the rating). It makes the forum much more useful when people can read about a problem and can know that they will also read a successful solution to the problem.

I am glad that I was able to provide some help and I encourage you to continue your participation in the forum.

HTH

Rick

bogdan.sass Mon, 02/19/2007 - 15:39

Once again, thank you for all your help! (and sorry about the little misinformation above - I could have sworn I had erased the startup config on the SDM routers! :| )

Richard Burts Mon, 02/19/2007 - 20:11

Bogdan

This just demonstrates a lesson that I seem to learn over and over again. Sometimes it is really helpful to go back to the equipment and try things because sometimes our memory plays tricks on us.

HTH

Rick

Actions

This Discussion