Cisco VSS-1440 migration query

Jason Giles jgiles at e-dialog.com
Mon Oct 19 17:06:16 UTC 2009


>From my test, all physical interfaces configs on switch 2 are factory defaulted and SVI interfaces deleted on switch 2 upon running the conversion commands.

Switch 1 is intact with the new naming convention as well as SVI's. 

I cannot comment on glbp as I do not run it.   




/Jason


-----Original Message-----
From: Leland Vandervort [mailto:leland at taranta.discpro.org] 
Sent: Monday, October 19, 2009 11:07 AM
To: nanog at nanog.org
Subject: Cisco VSS-1440 migration query

Hi All, 

Trying to find an answer to a single technical point concerning a
migration of a fleet of Catalyst 6500's to VSS-1440.

I've had a scan through the documentation on CCO (whitepapers, config
guides, migration guides, etc.) but cannot find anything dealing with
this one specific point.

Background:

Assume that on both stand-alone chassis, you have a specific vlan
interface with L3 configuration, such as:

switch1:

 vlan 10
  name testing
 !
 interface vlan10
  ip address 10.100.100.1 255.255.255.0
  glbp 1 ip 10.100.100.254 
  glbp 1 preempt
  glbp 1 load-balancing round-robin
 !

switch2:
  vlan 10
   name testing
  !
  interface vlan10
   ip address 10.100.100.2 255.255.255.0
   glbp 1 ip 10.100.100.254
   glbp 1 preempt
   glbp 1 load-balancing round-robin
  !

Once switch 1 is converted to VSS mode and is brought up as
ACTIVE/MASTER, it will keep it's layer3 configuration on the VLAN
interface. 

The question is what happens to the L3 configuration on switch2 when it
comes up in STANDBY/SLAVE?

I can foresee one of two possibilities, but not sure which to expect
before trying to do this in a live enviroment:

either: 

 1. switch2 will boot up straight into NSF/SSO, inheriting its [new L3]
configuration from the active master, overwriting the pre-VSS L3
configuration.   (would be preferable). 

or

 2. switch2 will boot up and enter RPR mode with incompatible
configuration for the interface, forcing me to have to manually remove
the L3 configuration from the interface before I can proceed with the
migration.  (not really ideal with hundreds of vlans on these things...)

Any idea which one of these would be the case ?

(the glbp will be retained, as it will be running between two VSS pairs
with 10G trunks between them).


Thanks in advance


Leland








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