9407R switch Sup-1 question on redundancy

[JaganV]

Hi guys,

I have a 9407R switch chassis running with just a single SUP-1 module.

However, we are bringing in a used secondary SUP-1 from another site, to add this into my switch as redundancy.

The thing is, the old SUP still has old config from the other site. How do I install this smoothly on the live system?

I don’t have a lab env to clear the old SUP first.

Thank you in advance.

[mohammedshahidali88]

Hi,

To install new SUP in your existing chassis, first of all you need a downtime to bring the switch down.

1. you have to take the back up of the switch.

2. Install the new SUP and bring it up and check the software version and bring both sup in same version.

show module

 3. after that you can review the config, if it got changed then update the config.

[mohammedshahidali88]

Also refer this document which will give you some updates for redundancy of SUP

https://www.cisco.com/c/en/us/support/docs/interfaces-modules/catalyst-9600-series-supervisor-engine-1/216193-replace-a-supervisor-module-or-stack-mem.html#toc-hId-3547633

[balaji.bandi]

some guide lines like we do RMA replacement procedure to add module :

https://www.cisco.com/c/en/us/support/docs/interfaces-modules/catalyst-9600-series-supervisor-engine-1/216193-replace-a-supervisor-module-or-stack-mem.html#toc-hId--296603800

[Joseph W. Doherty]

It could be a bit tricky, not so much due to a different config on the to be added sup, but due to a different IOS on the to be added sup.

From a brief scan of the documentation (I haven't any experience with the 9400Rs), if auto upgrade is enabled, when you insert the second sup, hopefully it will load up the IOS from the primary sup.  If it does, it may then show as a warm standby.  If so, you may need to save config to standby sup (but unsure about that).  You may also need to insure SSO is configured and active.

If standby does not autoload primary running IOS, you may need to load that IOS via that sup's USB module.

Some information I've been looking at:

https://www.reddit.com/r/Cisco/comments/tkhpuo/question_adding_a_new_standby_supervisor_blade_to/

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9400/software/release/16-10/command_reference/b_1610_9400_cr/high_availability_commands.html

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9400/hardware/sup_install/b-c9400-sup-note.html#id_53428

[Leo Laohoo · Accepted solution]

Before inserting the 2nd Supervisor Card, make sure the following command is already present: 

software auto-upgrade enable

[JaganV]

Yes this helped. The firmware was automatically synced. redundant SSO mode helped with the config sync too. Thank you so much!

[Joseph W. Doherty]

Again, no direct experience with that hardware, but even if IOS and config auto synced, you may need to insure both are actually saved to flash.

@Leo Laohoo can you comment on that aspect?

[Leo Laohoo]

Gone were the days when a new 3750X switch member cannot join a stack because the firmware needs to be manually upgraded first before it can join the stack.  

With the introduction of the command "software auto-upgrade enable" this allows any IOS-XE switch, whether it is a 3650/3850, 9200, 9300, 9400 or 9600 supervisor line cards, to join the stack automatically regardless the firmware version.  The only "catch" is the hardware revision.  There are some HW revision which have a minimum firmware.  If the the minimum firmware of a newer HW revision is higher than the stack, the new switch member cannot join the stack regardless.

However, because the obstacle of the firmware have already been answered, the configuration can easily synchronize with the switch master or the master supervisor card.

[Joseph W. Doherty]

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@Leo Laohoo wrote:

, the configuration can easily synchronize with the switch master or the master supervisor card.

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Got that, but does the IOS and config are automatically saved on the newly added secondary sup?

Very, very unlikely, but, say the 9400 chassis loses power and when power is restored the original sup fails.  Is the auto copied IOS and config physically stored on the previously added secondary sup?

[Leo Laohoo]

The command "software auto-upgrade enable" means the master supervisor card will immediately push the firmware down to the secondary/slave supervisor line card flash/bootflash. 

After the secondary/slave supervisor boots up in the same firmware as the master, the master supervisor will send a copy of it's config down to the "new" secondary/slave supervisor.  

After that, both master and secondary/slave are a single logical unit.  

I hope this helps.