topic Re: active/active HA with layer3 sub-interfaces in General Topics

active/active HA with layer3 sub-interfaces

ikunduraci — Fri, 10 Apr 2020 02:26:21 GMT

Hi all,

Is active/active mode supported with Layer3 sub-interfaces? I'm trying this in a lab with 2 VM-50's, and whilst the cluster is formed, I seem to have intermittent packet loss; not sure if this is just a limitation of the VM series (in particular, VM-50) or the fact that they are not true layer-3 interfaces? The customer has a pair of 5220's for a greenfield deployment, but we are planning on using layer3 sub-interfaces.

Both firewalls obviously have the same interface config (VLAN ID, tag etc;) albeit 1 node has IP's configured for VLAN 800-805, whilst the second node has IP's configured for VLAN 806-810. VR is not sync'd between the firewalls and each firewall has individual BGP peerings to the upstream and downstream router.

The vSwitch with HA3 interface has MTU 9000. Session owner and session setup is set for first-packet.

We require active/active due to asymmetric paths; the routers see ECMP paths through each firewall so depending on the hash, we can't guarantee return traffic through the same firewall node.

Re: active/active HA with layer3 sub-interfaces

reaper — Wed, 15 Apr 2020 05:35:49 GMT

Yes this is supported

Have you found any indication why and where packet loss occurs? Not sure if a VM environment is the best place for AA

Re: active/active HA with layer3 sub-interfaces

ikunduraci — Thu, 16 Apr 2020 07:40:24 GMT

Thanks Reaper - I managed to fix my issue, it was related to the fact that the interface names were different; I got caught up on the interface name having a .VLANID (e.g. eth1/1.800), I can probably blame Cisco for that 🙂

After matching the interface names (and modifying VLAN tags accordingly), all works well.

Cheers