Expand all | Collapse all

Migrating from MCLAG with VRRP to EVPN

  • 1.  Migrating from MCLAG with VRRP to EVPN

    Posted 02-05-2021 16:05

    Our campus environment is currently setup with 2 MX routers acting as MC-LAG peers. VRRP is configured among the 2 MX routers to provide gateway redundancy for all irb networks routed at the MX router.

    The MX routers then connect upstream to the MPLS core using protocols such as MPLS, LDP and OSPF.

    Would it be possible to migrate the MC-LAG configuration with EVPN configuration?


  • 2.  RE: Migrating from MCLAG with VRRP to EVPN

    Posted 02-07-2021 07:16
    Short answer: Yes

    The approach depends a bit on how long downtime you can accept during the change as I haven't heard about any scenario where you have MC-LAG on one MX and EVPN on another... but an approach like this can with proper planning limit downtime to a few minutes and even less:

    1. Reconfigure relevant BGP peers to signal EVPN (Ensure your route-reflectors (if any) are configured to handle evpn-signaling)
    2. Close downlinks from MX-B and disable ICCP configuration
    3. reconfigure MX-B to handle irb's and bridge-domains via EVPN
    4. Configure physical downlink interfaces on MX-B to be a part of matching ESI LAG groups
    5. Close downlinks on MX-A and enable on MX-B...
    6. Convert MX-A from MC-LAG to EVPN...

    There are a lot of steps in between but properly planned the downtime should be very low.. and give you flexibility on a longer perspective :-)

    Jonas Hauge Klingenberg - Juniper Ambassador