Restore running-config and vlan.dat

[Beaurr]

Hello,

I would like to restore running-config and vlan.dat on a cisco 3850 switch.
I have the old configuration on a txt file.
On the switch, I have the startup config file in the nvram folder.
On the other hand, the vlans do not appear in the conf, they are stored in vlan.dat?
How to restore the 2 (cong + vlan.dat?)

[balaji.bandi]

depends on your environment, if this is standalone device - you can copy your backup config and vlan.dat file should restore.

if this is part of the network if you have VTP Server, the VLAN will sync automatically.

here is some guide :

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-2940-series-switches/109304-manage-vlandat.html

[kapydan88]

Hello.

First, you need to check vtp status for new switch. Second, you need to check encryption for password in your current config - if passwords are encrypted, its must be specified in an unencrypted feed. 

Also, in startup-config you need to check vlan list.

[Beaurr]

Iokay
This is not a new switch but the same. More specifically, it's a switch stack.
Changes have been made in confs and deleted vlans, and since then we have had weird behavior on the switch. So, I was asked to restore the stack to a version prior to the modification.

[balaji.bandi]

if this is a standalone stack or part of the VTP domain?

if this standalone - my procedure still valid do this on Master switch.

1. take exiting switch config and vlan.dat back up out of the box.

2. in the maintenance window - do the steps are suggested other posts.

[Beaurr]

ok thanks.

the stack is part of the VTP domain.

[balaji.bandi]

if the static is part of the VTP domain, not a Server Role, Configure just VTP version and Mode to the client - so all the vlan database will be pushed from server to client.

here are the steps in related to config :

take exiting running-config / backup config  in notepad or excel

compare each one whatever line missing adding to switch and write to resolve the issue.

Other notes: I forgot to ask you what wierd issue you see (examples, logs, ) nice if you can post old back up the config, removing confidential information to understand.

[Beaurr]

Thanks.

the switch is VTP server.

The weird issue is, for exemple, from my PC in a vlan with no access-list, i can ping the 2 interfaces on my asa ( failover active / standby).

My colleague, in the same vlan, can't ping the interface of the ASA.

We have reloaded the core switch last week, without result.

other problem, We have an  ASA ( in failover active/standby) , every 3 days, at about the same time (between 2h and 2h30 in the morning) crashes. and becomes inaccessible.
We are forced to restart it electrically, after, it works normally, for 3 days ... then we have to start again.
All these problems appeared the day after  we deleted old vlan configured on the core.
So my manager asked me to restore the configuration of the core network as it was before the modifications.

We have a server which saves the conf of all our equipment in txt files, every evening.
it also saves in an html, the configuration with the modifications made (before / after)

[balaji.bandi]

How was this situation occurred, any Power Loss, Failure of devices ? or any IOS Upgrade?

If this is VTP Server,  then you need to have all the VLAN present in this switch.

your configuration backup all the information ( past good working config) - as I have suggested, compare the config and add the missing information to current config, or copy the config to overwrite and reload the stack.

Then Monitor, as part of this troubleshoot configure any Syslog server and offload the load the logs to Syslog server, it will give you more visibility some of the logs may override or lost after reboot.

[Beaurr]

what I plan to do is:
restore via tftp the startup config file saved the day before problems on the core network

restart the network core

the startup config and the running config will be identical after that normally?

All vlans are well declared on the config file

but the configuration of the VTp server, with the domain etc ..., are not.

The configuration of the VTP is in the vlan.dat?
i will share here the result of syslog server monday.

[balaji.bandi]

Good progress keep us update, and post the logs.

[Beaurr · Accepted solution]

hello,

thanks for your  help.

The problem is solved. The heart has been restarted.

ASA issues were resolved with a firmware update

[kapydan88]

"This is not a new switch but the same. More specifically, it's a switch stack" - is this layer 3 switch (with ip routing) or layer 2 (without ip routing). I have had to deal with memory leaks on this series 3850 in stack mode with "ip routing".

A simple reboot didn't always help. There is a different solution for this problem - turn off both switches in the stack, pull out all the power cables and insert them back. I'm not sure what will help in this particular case, but it's worth a try.