Cisco 4500x configure fast-hello interface with multiple ports

Question

I have a pair of cisco 4500x-32 and i configured VSS between then but i am using just 1x 10G interface for fast-hello packet and here is that interface configuration:

interface TenGigabitEthernet1/1/2
 description VSS-Fast Hello
 dual-active fast-hello
end

I want to have redundancy for this interface, so i can execute "dual-active fast-hello" on another 10G interface for the fast-hello packages, or Shall i bundle both ports are port-channel then issue "dual-active fast-hello" command under port-channel interface?

if we should not use port-channel and we should have two phsycally interface with "dual-active fast-hello" under their configuration, Do they working as redundancy? my mean is if the first port goes down, Is the second port responsible for the fast-hello packets?

Answer 1

You can/should use port channels for the Virtual Switch Link between the 2 switches.

You can use up to 4 ports/connections between the VSS switch members for active detection (assuming you don't want to use ePAGP or BFD).

Each port needs to be configured as 'dual-active detection ports'. They should be connected directly to each other and should probably just be 1 gigabit ports, no need for 10 gigabit or faster because they are simply for 'hello' state detection traffic.

You should make sure that the ports you choose are not on oversubscribed line cards where frame queuing or drops might prevent hellos from being sent/received which could result in inappropriate failover of the active switch role.

These links provide more specific configuration information and some additional commentary:

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/XE3-8-0E/15-24E/configuration/guide/xe-380-configuration/vss.html

https://netcraftsmen.com/cisco-vss-dual-active-detection/