[c-nsp] EVPN-VPWS PW and AC status coupling

[adamv0025 at netconsultings.com]

> Marco Marzetti
> Sent: Friday, February 09, 2018 10:34 AM
> 
> Hello,
> 
> It's been a few weeks I've been working on EVPNs and IOS-XR 6.1 and i
> wonder if ther's a way to couple AC and PW status so that you can
propagate
> PE-CE link failures end-to-end.
> 
> I know it's supported for "regular" EVPNs (RFC7432), but EVPN-VPWS
> (RFC8214) is definitely a special case.
> 
> Here's my configuration snippets
> 
> !
> hostname XRV1
> !
> interface GigabitEthernet0/0/0/0.200 l2transport  encapsulation dot1q 200
!
> router bgp 64496
>  bgp router-id 192.0.2.1
>  address-family l2vpn evpn
>  !
>  neighbor 192.0.2.2
>   remote-as 64496
>   local address 192.0.2.1
>   address-family l2vpn evpn
>   !
>  !
> !
> l2vpn
>  xconnect group test
>   p2p test
>    interface GigabitEthernet0/0/0/0.200
>    neighbor evpn evi 100 target 300 source 200
>   !
>  !
> !
> 
> 
> !
> hostname XRV2
> !
> interface GigabitEthernet0/0/0/0.300 l2transport  encapsulation dot1q 300
!
> router bgp 64496
>  bgp router-id 192.0.2.2
>  address-family l2vpn evpn
>  !
>  neighbor 192.0.2.1
>   remote-as 64496
>   local address 192.0.2.2
>   address-family l2vpn evpn
>   !
>  !
> !
> l2vpn
>  xconnect group test
>   p2p test
>    interface GigabitEthernet0/0/0/0.300
>    neighbor evpn evi 100 target 200 source 300
>   !
>  !
> !
> 
> 
> What i'd expect is XRV1 to turn Gi0/0/0/0.200 down when XRV2 withdraws
> the BGP advertisements.
> 
> Is that supported?
> 
Hmm I'm getting a bit rusty on the Carrier-Ethernet stuff but isn't that the
other way around?
I mean what I remember is that if AC goes down that in turn brings down the
PW -but the bit where the PW failure propagating to the other end then in
turn brings the AC down on that end too  -that one I don't recall to be
honest.  (Would I need to enable that with some knob first?) 
And what if the other end is configured with PW-redundancy -in that case I'd
need the AC at remote end to stay up and just use the backup PW. 

Sure if you run LFM or the whole CFM suite end-to-end, then that could bring
down ACs at both ends in case any component along the path fails. 
 
 
adam

netconsultings.com
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