[j-nsp] EVPN all-active toward large layer 2?

[Krzysztof Szarkowicz]

Hi Rob,

As per RFC, bridges must appear to EVPN PEs as a LAG. In essence, you need to configure MC-LAG (facing EVPN PEs) on the switches facing EVPN PEs, if you have multiple switches facing EVPN-PEs. Switches doesn’t need to be from Juniper, so MC-LAG on the switches doesn’t need to be Juniper-flavored. If you have single switch facing EVPN PEs -> simple LAG (with members towards different EVPN PEs) on that single switch is OK.

Thanks,
Krzysztof


> On 2019-Apr-18, at 08:35, Rob Foehl <rwf at loonybin.net> wrote:
> 
> On Thu, 18 Apr 2019, Krzysztof Szarkowicz wrote:
> 
>> Hi Rob,
>> RFC 7432, Section 8.5:
>> 
>>   If a bridged network is multihomed to more than one PE in an EVPN
>>   network via switches, then the support of All-Active redundancy mode
>>   requires the bridged network to be connected to two or more PEs using
>>   a LAG.
>> So, have you MC-LAG (facing EVPN PEs) configured on your switches?
> 
> No, hence the question...  I'd have expected ESI-LAG to be relevant for EVPN, and in this case it's not a single "CE" device but rather an entire layer 2 domain.  For a few of those, Juniper-flavored MC-LAG isn't an option, anyway.  In any case, it's not clear what 8.5 means by "must be connected using a LAG" -- from only one device in said bridged network?
> 
> -Rob