4500X-16 VSS issues

[sdawson35]

Hi,

We have a pair of 4500X-16's running in VSS mode, we have an issue that when the primary fails we lose all external routing.

They are running a comparatively old IOS version - 3.6.3E (ROM 15.0(1r) SG12)and I know that has some bugs in in it so maybe a contributing factor ?

We have 2 interfaces from our ISP 1 in the primary and 1 in the secondary , these are trunked vlan ports.

interface TenGigabitEthernet1/1/16
description *** Primary link ***
switchport trunk native vlan 66
switchport mode trunk

----------------------------------

interface TenGigabitEthernet2/1/16
description *** Secondary link ***
switchport trunk native vlan 66
switchport mode trunk

-------------------------------

vlan 66
name VM_Vlan

-------------------------------

interface Vlan66
description Router_Vlan
ip address 172.31.1.217 255.255.255.248

---------------------------------

ip route 0.0.0.0 0.0.0.0 172.31.1.218

--------------------------------

I am only guessing but believe the issue not to be with the 4500 but the ISP ?

[Leo Laohoo]

I'm going to take a guess and say "upgrade" the firmware first.

[balaji.bandi]

As suggested upgrade the IOS, also like to see your network topology, how you connected these switches to ISP network ?

[mnagired]

Hi,

For Sub-Second convergence with VSS, you need a routing protocol neighbor ship and NSF/Graceful restart enabled.. From the configs shared, i only notice a Static route configured and with static routing you cant achieve a sub-second convergence.. 

Regards

Mahesh N

[Reza Sharifi]

Hi,

This is not an IOS, hardware or software issue.  This is most likely a design issue. If you have 2 different ISP, how is that that your static route is pointing to one IP only?  What is design look like? Most ISPs don't do layer-2 with their customers, I am curious how you are connected to the providers. Are these ISPs providing your Internet access?

HTH

[sdawson35]

Not 2 different ISP's , the same ISP, Primary and secondary routers 1 into each of the 4500's .

I have included a basic Visio diagram , might help.