topic Re: Unable to priorize an external route into IS-IS redistribution in ExtremeSwitching (VSP/Fabric Engine)

Unable to priorize an external route into IS-IS redistribution

Jave — Tue, 02 Jul 2024 13:05:41 GMT

Hi everybody,

I'm facing a problem setting up a lab. This is my goal:

* I have a lab with 3 VOSS devices forming a SPB Fabric
* 2 of them have each one a BGP IPv4 peering learning the external default route; they redistribute this route into IS-IS in a specific VRF

* Third VOSS simulate a client access switch. Interconnection with third party client's device is done via a local VLAN into a dedicated public subnet.

* the setup use a L3VSN into the VRF between this client VLAN and the 2 VLANs dedicated to BGP peering.

All is working fine, access switch retrieve default external route to either VOSS BGP peer BUT I can't priorize systematicaly one preferred default route.

How can I achieve that ?

Re: Unable to priorize an external route into IS-IS redistribution

EF — Tue, 09 Jul 2024 10:58:38 GMT

Hi Jave,

maybe using route-map

How To: VOSS - How to redistribute only listed static routes into ISIS by using route-map? | Extreme Portal (site.com)

And with the command "set ip-preference X" you can change the preferences from one node.

Regards

Re: Unable to priorize an external route into IS-IS redistribution

Jave — Tue, 09 Jul 2024 13:20:27 GMT

Hi @EF

Yes, I haven't posted the solution I've found, but this is it (creating a VRF VIDEO accepting only default route; I set ip preference 50 for isis in order to priorize the same route learnt via BGP of which default ip preference is 45):

router vrf VIDEO ip prefix-list "DEFAULT" 0.0.0.0/0 route-map "ISIS-DEFAULT-PREF" 1 permit enable match network "DEFAULT" match protocol isis set ip-preference 50 exit isis accept route-map "ISIS-DEFAULT-PREF" exit isis apply accept vrf VIDEO

Regards.