configure virtual MAC in vrrp setupt on ncs router

[rhanisch_01]

Hi, 

I have a question regarding the configuration of a virtual MAC address in a VRRP setup on an NCS router. We are currently in the process of migrating our ASR9001 router, which has an HSRP configuration, to an NCS router with VRRP configuration. To ensure a smooth migration, we would like to configure the virtual HSRP MAC address into the VRRP setup.

I have been searching through the documentation but haven't been able to find any information on whether this is possible. 

 Regards

[balaji.bandi]

have you looked this configuration guide ?

https://www.cisco.com/c/en/us/td/docs/iosxr/ncs5500/ip-addresses/24xx/configuration/guide/b-ip-addresses-cg-ncs5500-24xx/implementing-vrrp.html

[Joshqun Ismayilov]

VRRP typically uses its default MAC address format, configuring a custom virtual MAC (like the HSRP MAC) may not be natively supported on NCS routers. You can achieve a seamless migration by using static ARP entries, minimizing preemption delays, or temporarily dual-stacking HSRP and VRRP.

[Giuseppe Larosa]

Hello @rhanisch_01 ,

from the document provided by @balaji.bandi we see:

Virtual MAC address is 0000.5E00.010a, state is active
Master router is local

so I agree with @Joshqun Ismayilov . In IOS XR also on ASR9001 we define the router vrrp and we associate it with a BDI that acts as the L3 interface for a locally switched l2vpn.

So the strategy proposed by @Joshqun Ismayilov is probably the best one to minimize traffic disruption.

You can insert the new devices in parallel with current ASR9001 and you can test the new NCS on selected end user hosts or selected downstream devices by using a combination of static ARP entries or even using a different VIP address for VRRP and changing the static routes for downstream devices.

Hope to help

Giuseppe

[rhanisch_01]

Hi all, 

I have tested thi mirgation in my CML Lab. I can confirm that dual-stacking with HSRP and VRRP achievable, but I have an issue when i deconfiguring the router HSRP – the traffic was lost. The traffic resumed when I reset one of the interfaces. The optimal solution for me was to configure VRRP and deconfigure HSRP simultaneously on both routers by using the commit command. The traffic lost was very small (3Pings). The tests were performed without static ARP entries. I will it check it in the next time.

Regards