Hello, We've been testing different point-to-point L2VPN services on 7600 as PE routers (in MEF terminology ERS, EWS).
Basically the topology is this: CE------[ME3600]------[7600]----MPLS-----[7600]---------enni(dot1ad)-----[7600]--------[ME3400]----CE ^ ^ | | | | QinQ QinQ The idea is that we have (from right to left) an ISP send us S-tagged customer frames over ENNI, which we then transport over MPLS to leftmost 7600, which takes out topmost S-tag and forwards frames to customer on other side. I think this would be called EWS in MEF terminology or transparent EPL (not port-based) in Cisco. Anyhow this is the configuration on rightmost WS-card 7600 (which would belong to other ISP) facing 3400: interface GigabitEthernet switchport switchport access vlan XXX switchport mode dot1q-tunnel l2protocol-tunnel cdp l2protocol-tunnel lldp l2protocol-tunnel stp l2protocol-tunnel vtp no cdp enable spanning-tree bpdufilter enable end Same 7600 facing our 7600 over ENNI link: interface GigabitEthernet switchport switchport trunk encapsulation dot1q switchport trunk allowed vlan XXX switchport mode trunk ethernet dot1ad nni end Then, our (middle) 7600 (ES+ card) facing ENNI link: interface GigabitEthernet no ip address ethernet dot1ad nni service instance XXX ethernet encapsulation dot1q XXX rewrite ingress tag pop 1 symmetric bridge-domain XXX ! end There's also interface vlan XXX which XCONNECT-s to our leftmost 7600. Finally, leftmost 7600, WS-card facing 3600: interface GigabitEthernet switchport switchport access vlan XXX switchport mode dot1q-tunnel wrr-queue cos-map 2 2 4 wrr-queue cos-map 3 1 7 wrr-queue cos-map 3 2 3 6 l2protocol-tunnel cdp l2protocol-tunnel lldp l2protocol-tunnel stp l2protocol-tunnel vtp no cdp enable spanning-tree bpdufilter enable end Here's the thing: ------------------------ Tagged L2CP (cdp/stp...), as well as any other customer traffic is transported fine. 3600 and 3600 see each other. But when it comes to untagged traffic, both switches put their interfaces in inconsistent STP state and block VLAN1 traffic over their trunks. As far as I could understand, the receive BPDU containing S-tag info, over Vlan 1. I would understand if this happened over normal trunks where different native vlans are used. But this is our S-tag, and I don't think customer switches should be able to see anything containing our S-tag. Could anyone shed some light on this? Is it possible to transport UNTAGGED traffic/L2CP with this configuration? regards _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
