ERS 5510 2 Units Stack / Config Backup and Restore

[nicko]

Hello all,

I have a problem with config backup and restore and i hope i will find some answers here !

Informations about the switches :
Ethernet Routing Switch 5510-48T
BOSS 6.0 SSH
HW:03       FW:6.0.0.9   SW:v6.1.1.017

Introduction :
I have a Stack of 2x 5510-48T running in production with different VLAN, MLT, STP setup ...
I've made some test to make a process to replace a switch in case of a unit failure (base or not).

The process is the following :
Prerequisites :
1/ I need to have a binary backup of the stack.
2/ I need to have the firmware and software used in the stack.
3 As i am in a 2 Units Stack, AUR and AAUR are disabled, Stack Forced Mode is enabled.

Process :
1/ I take a new switch.
2/ I reset the new switch to factory default.
3/ I upgrade the firmware and the software to match the stack.
4/ I push the binary backuped conf of the stack on the new unit with (<Unit_Number is the number of the unit i want to replace) :
    copy tftp config address <TFTP_IP> filename <Binary_Stack_Config> unit <Unit_Number>
5/ I replace the dead unit with the new one and i turn it on .
6/ i renumber the units to match the original config
=> Let say the original units numbers were (1 and 2), after the insertion of the new unit, i will have (1 and 3) or (2 and 3)

I've tested this process several time and it works perfectly ...

The problem is the following :
When i want to inject the backuped config of my production stack and install it in a new stack, it doesn't work at all.
I tried to make a new stack, then to inject the binary backup and , let say the original stack was (Base Unit: 1 and Other Unit: 2) with all my interfaces named 1/x and 2/x and so all the interface references in the MLT and VLAN were 1/x and 2/x, what i've got after the binary backup injection is a stack  (Base Unit: 3 and Other Unit: 4) with all the interface references in MLT and VLAN in 2/x and 3/x !

Whatever i do, i always have ghosts references to a switch that does not exist anymore :
- I tried to renumber the units, the references are changing but don't  match my config
- I tried to replace the units that are missing and the renumber the units, the references are good in the VLAN but the MLT still have ghosts references to a switch that is not there anymore.


Do you know if there is a process to manage this situation ie to inject a conf of a stack in another brand new stack ?


Thanks,
Cheers.
Nicko

[nicko]

Hello,

Nobody would have a clue ?

Thanks !
 

[Michael McNamara]

Hi nicko,

Sorry for the late response... replacing a switch within a stack can be a hit or miss experience depending on software version.

While there are some "features" available to help with the process I generally stick with the basics... because this process will work everytime regardless of the software release or the general configuration.

I backup both the binary and ASCII configuration every Friday evening to a TFTP server, I also archive those configurations for 4 weeks.

If you have a switch failure you can replace the switch, factory default the stack (the entire stack of switches) and then perform a initial configuration to restore connectivity to the network and then restore the ASCII configuration from the TFTP server.

You can certainly use the process/procedures you've outlined below, you just need to be careful that some things might behave differently based on configuration and/or software release.

You will certainly need to "re-number" the stack... the stack configuration hold the base MAC address of every switch in the stack. When you replace a switch you need to tell the configuration that you've replaced a switch and to use the new MAC address of that switch. You can do that with the stack re-numbering command.

There is also a feature called Auto Unit Replacement (AUR) which provides another method... have a look at this post and the comments for a discussion.
http://blog.michaelfmcnamara.com/2008/07/ethernet-routing-switch-5500-stack-troubleshooting/

Good Luck!

[nicko]

Hello Michael,

Thanks for your answer and for your job on this forum by the way, it's a really helpfull information source for Nortel Devices !

For my problem :
As i told you, when it comes to replace *1* switch in the stack, everything is fine, what i want to do is to clone the configuration on a brand new stack, and here the nightmare begins !
I tried to inject the ascii config a lot of time but it always failed ... I saw somewhere that the switch can not accept the global ascii file but only some part of it, so the only solution i got is to inject the parts i'm interested in ...
It's a really boring task and i can not be sure that i will got everything i need to have a stack with the exact same setup  i had before.

I think i will have to develop a script  for that specific purpose.

Thanks !
Nicko

[Michael McNamara]

Hi nicko,

Thanks for the kind words... you can certainly 'clone' a stack using the ASCII configuration feature. I've done it dozens of times without much trouble. You need to make sure the new stack has the same version of software, the stack also needs to be at a factory default state or the ASCII configuration file might not take properly.

The issue is that the ASCII configuration file expects the switch/stack to be in a factory default state. If you try to load a ASCII configuration file to a switch/stack that doesn't have a factory default configuration you'll like end up with a lot of issues.

Good Luck!