Cisco VSS-1440 migration query

Mailman List Mirror (Read Only)
1

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

2

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

3

>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.

This one is alarming, especially given that there may well be some
physical interfaces that are only present/used on one of the two chassis
in the group. Would be interesting to see if they are defaulted to
factory or not. (I would expect unused ports to be defaulted, but not
ones actually configured and actively in use). Don't suppose you're
able to test that one?

However, this sounds like good news for the VLAN/virtual interfaces
though.

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.

The glbp isn't really that much of a worry since those are being
converted from HSRP anyway so will have to manually do those.

/Jason

Thanks dude... sounds like it partially answers my question, but raises
another :wink:

L.

4

defaulted and SVI interfaces deleted on switch 2 upon running the
conversion commands.

When you convert to vss mode the interfaces are renamed. The interface
in switch 2 that was g1/1 becomes 2/1/1. Any configuration applied to
g1/1 will be rejected because that interface no longer exists. If you
intended to keep interface configuration, you will need to reapply that
to the new interface name.

Jason

5

Thanks to all on this.

I've pretty much mitigated this by creating a VSS-ized version of the
interface configs (chassis/slot/port) which I can then re-inject back
into the system config after conversion.

Shame that switch1 keeps its config and simply renumbers the interfaces,
but switch2 just says "I here am new" .. but oh well.

Leland