Should I be using point-to-point or broadcast if I plan on using SVIs in IS-IS on Juniper?

Question

Apologies in advance if this is super-basic question, still learning ISIS.

I'm migrating from Cisco over to Juniper in an environment where all of the switches are running EIGRP, are on a 172.31.255.0/24 segment which is an SVI (VLAN 9) and they reach each other via trunk links. I will be adding Juniper switches into this environment, configuring them to run IS-IS.

My question is, if I plan to keep the same SVI subnet on my Juniper switches and run IS-IS, would I configure a point-to-point statement under the SVI interface or would I make it broadcast since technically it's just one giant VLAN?

My long term plan is to eventually cut down on all the VLAN sprawl and go EVPN/VXLAN but I would like IS-IS as my IGP. Thanks.

Answer 1

Whether you use broadcast or explicit P2P doesn't really matter for a small number of routers/L3 switches. With larger numbers, P2P creates more overhead and becomes harder to maintain .