Can I do this in EVPN? (Multihome to more different CEs)

Jason R. Rokeach jason-at-nanog.lb61g at
Thu Feb 9 19:11:21 UTC 2023

VPLS doesn't handle loop avoidance. At least, not apart from split horizon rules.

I assume that them properly connecting routers only and doing dynamic routing over your service is out of the question? (Even _just_ doing this doesn't completely solve the challenge though.)

It sounds to me like your customer is needing two separate services. One to provide connectivity to other sites at layer 2, and another to provide backup connectivity within their single campus at layer 2. I would suggest that you treat these as two separate services, because there's nothing in EVPN that's going to notice on the PE side of the equation that the customer has a break in the middle of their network.
Maybe consider offering these two services in combination:
1) layer 2 VPN service (VPWS / single pseudowire) between the two sides of their campus. You would need to ensure L2CP transparency (or tunneling) for STP and they would need to run STP across the link to keep their campus whole
2) EVPN with ESI in single-active mode, as you had mentioned.

------- Original Message -------
On Thursday, February 9th, 2023 at 11:56 AM, Simon Lockhart <simon at> wrote:



> On Thu Feb 09, 2023 at 11:54:28AM -0500, Shawn L wrote:

> > You should be able to setup a VPLS between 3 (or more) devices. Something like this --


> [snip]

> Thanks - I'm not committed to EVPN, so VPLS could work too. Would VPLS
> handle loop avoidance for me? (i.e. if I have two VPLS PE connections into
> the same broadcast domain on the customer side)

> Simon

Jason R. Rokeach
m: 603.969.5549
e: jason at
tg: jasonrokeach

Sent with ProtonMail secure email. Get my PGP Public Key.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 249 bytes
Desc: OpenPGP digital signature
URL: <>

More information about the NANOG mailing list