Add extra new Stackwise virtual link (SVL)

[TariqAlmouti72833]

Dears

I currently have 2 x C9500-24Y4C connected via 1 x 10GB Stackwise-virtual link (SVL) and it's up and running.

I would like to add a second SVL 10GB link for redundancy and greater throughput. 

If I go with adding the port and configure it, should I need to restart the switch to make the new link run? and am I gonna face any downtime or network interruption? or it will go smoothly with no interruption on the network?

Regards

[Reza Sharifi]

Hi,

You should be able to add a second port to the Porchannel and there is no need to reboot. That said, I would have a maintenance window and do it during off hours just in case something unexpectedly goes wrong.

HTH

[Francesco Molino · Accepted solution]

Hi

Never added a link afterwards and i would have thought there’s no need to reboot but FAQ official doc says differently:
After StackWise Virtual conversion, any addition to or removal from SVL or fast hello connection will require both stack members to reload to make the configuration effective.

https://www.cisco.com/c/dam/en/us/products/collateral/switches/catalyst-3850-series-switches/q-and-a-c67-738577.pdf

[heleros]

You have to reload both switch to activate a additional port.
But the Cisco TAC told me with the command redundancy force-switchover you are able to add a Stackwise Link or DAD Link without any outage, but i didn't try it yet.

[Reza Sharifi]

Thanks for the feedback!

Let us know if it works without reloading both switches. It is absurd and such a bad design if you have to reload both switches simply because you are adding an extra link to the SVL.

HTH   

[Francesco Molino]

Yeah i would be interested to know it that works. I hope so and this will means the doc isn’t to explicit.

[hans.goes]

Situation : 

2 x Cisco 9500-16X

Active SVL on Te1/0/15 <> Te2/0/15

Tried to add second SVL on Te1/0/14 <> Te2/0/14 via redundant fiber-route :

CSW(config)#int te2/0/14
CSW(config-if)# stackwise-virtual link 1
WARNING: All the extraneous configurations will be removed for TenGigabitEthernet2/0/14 on reboot
INFO: Upon reboot, the config will be part of running config but not part of start up config.

CSW(config-if)#int te1/0/14
CSW(config-if)# stackwise-virtual link 1
WARNING: All the extraneous configurations will be removed for TenGigabitEthernet1/0/14 on reboot

I tried rebooten switch 2 first but the Te1/0/14 stayed in SHUTDOWN

Te1/0/14                       admin down     down     StackWise-Virtual Link #1 (MER1 > SER2 fiber 3/4 > MER2)
Te1/0/15                       down           down     StackWise-Virtual Link #1 via MER1 Fiber

CSW(config)#int te1/0/14
CSW(config-if)#no shut
                                 ^
% Invalid input detected at '^' marker.

I also tried to reboot switch 1, no luck again.

Therefor I had to reboot both members at once :

CSW#   reload

System configuration has been modified. Save? [yes/no]: yes
Building configuration...
Compressed configuration from 21280 bytes to 9750 bytes[OK]Reload command is being issued on Active unit, this will reload the whole stack
Proceed with reload? [confirm]

After it came back :

*Sep 30 2020 13:12:55.312 UTC: %LINK-3-UPDOWN: Interface TenGigabitEthernet2/0/14, changed state to up
*Sep 30 2020 13:12:55.318 UTC: %LINK-3-UPDOWN: Interface TenGigabitEthernet1/0/14, changed state to up
*Sep 30 2020 13:12:55.317 UTC: %NIF_MGR-6-PORT_LINK_UP: Switch 1 R0/0: nif_mgr: Port 14 on front side stack link 0 is UP.
*Sep 30 2020 13:12:55.317 UTC: %NIF_MGR-6-PORT_CONN_PENDING: Switch 1 R0/0: nif_mgr: Port 14 on front side stack link 0 connection is PENDING.
*Sep 30 2020 13:12:55.311 UTC: %NIF_MGR-6-PORT_LINK_UP: Switch 2 R0/0: nif_mgr: Port 14 on front side stack link 0 is UP.
*Sep 30 2020 13:12:55.311 UTC: %NIF_MGR-6-PORT_CONN_PENDING: Switch 2 R0/0: nif_mgr: Port 14 on front side stack link 0 connection is PENDING.
*Sep 30 2020 13:12:56.311 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet2/0/14, changed state to up
*Sep 30 2020 13:12:56.318 UTC: %LINEPROTO-5-UPDOWN: Line protocol on Interface TenGigabitEthernet1/0/14, changed state to up
*Sep 30 2020 13:13:00.715 UTC: %NIF_MGR-6-PORT_CONNECTION_STATUS_CHANGE: Switch 2 R0/0: nif_mgr: PORT lpn:14 changed state from Pending to Ready.
*Sep 30 2020 13:13:00.715 UTC: %NIF_MGR-6-PORT_CONN_READY: Switch 2 R0/0: nif_mgr: Port 14 on front side stack link 0 connection is READY.
*Sep 30 2020 13:13:01.707 UTC: %NIF_MGR-6-PORT_CONNECTION_STATUS_CHANGE: Switch 1 R0/0: nif_mgr: PORT lpn:14 changed state from Pending to Ready.
*Sep 30 2020 13:13:01.707 UTC: %NIF_MGR-6-PORT_CONN_READY: Switch 1 R0/0: nif_mgr: Port 14 on front side stack link 0 connection is READY.

[heleros]

You have to reboot the switch via redundancy force-switchover. Only this command works to add a additional SVL Link and you have to do it twice.

There is a outage of 1sec/1Ping. If you reboot the whole Stack, then you have an outage of 10min.

[loizosko]

did anybody try the redundancy force-switchover?

[MARTIN THEINER]

I´m going to test it tomorrow.

We previously wanted to use 40Gig, but we had the 40/100 bidi which only goes 100 meters... so we had to step back to 10 gig.

Therefor I changed both links on the first box to 10 gig.

Afterwards i did the same on the second box, but only one of both links was correctly added to the running-config.

So i added the second link on the second box again... and now we have the same situation.

I´ll keep u updated

[Nuno P]

I know this is an old port, but has anyone tried this "redundancy force-switchover" to add a second stackwise virtual link? did it work?

[pwwiddicombe]

It kind of looks like the 9500X ones might allow it, but not what you have.

Dynamic addition and removal of SVL links are supported on the Cisco Catalyst 9500X Series Switches, and therefore, a reload is not required for adding or removing the SVL links when the device is already operating in SVL mode.