cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
2027
Views
0
Helpful
3
Replies

VSS and erasing the configuration

scott.leonard
Level 1
Level 1

I have two new 6807 switches in my R&D lab that will soon replace my existing core switches. I have used the lab time to test how the new switches handle various existing configurations. Now that I am finished testing I would normally do a write erase, restart and then apply the finished config but we are going to use VSS on these new cores rather than HSRP that we've been using on the old ones.

VSS does not like write erase because it also removes necessary ROMMON variables needed for VSS. Alternatives I have seen are:

1) revert back to stand-alone, wr erase, then re-configure VSS and apply my final config.

2) painstakingly remove unwanted configuration commands one by one using the no command.

3) issue the erase nvram command instead, reboot and apply my final config

4) issue the erase start command instead, reboot and apply my final config.

I would prefer either 3 or 4 because they are obviously less work and easier so which one would be preferable? erase start only gets rid of the startup-config and leaves the other files in nvram such as privat-config, underlying-config, rf_cold_starts, persistent-data, ifIndex-table, and snmpid-file.

So, should I erase just the startup-config, everything in nvram or should I bite the bullet and revert to stand-alone mode before erasing anything?

3 Replies 3

Reza Sharifi
Hall of Fame
Hall of Fame

So, I guess the question is why would want to remove the VSS config at all?

You can use the same VSS config from the lab to production.  Just remove the configs you are not going to be using in production.  If this is too much work, than I would do solution number-1. This solution requires a couple of reboots, but each reboot usually takes less than 10 Minutes.

HTH

Thanks for replying.

I don't want to remove the VSS config. I just want to remove all the junk in startup-config left over from R&D.

Normally I would just write erase and reboot before applying my final config but write erase is a big no-no after VSS has been set up. Cisco's VSS configuration guide says to revert back to standalone before doing a write erase. Cisco's VSS Best Practices doc also says write erase is a big no-no but that the command "erase nvram" will work because it leaves the "switch-id" variable in ROMMon.

The only reason I would remove VSS is if I thought the erase commands too risky and might break the VSS leaving the switches in a broken state.

Correct.  I would not want to use any of the erase commands and be in a situation where VSS is not functioning correctly anymore. I think, it is safer to do option-1 manually and than rebuild it or just remove the extra junk you don't need.  Unfortunately there isn't an easy way to do this in Cisco IOS.

Good Luck!

Review Cisco Networking for a $25 gift card