Joe, Did you check for MTU issues? IPv6 has different MTU requirements than IPv4, and the setup you are describing is prone to MTU issues due to the reduced MTU on the L2 transport.
Arie -----Original Message----- From: cisco-nsp-boun...@puck.nether.net [mailto:cisco-nsp-boun...@puck.nether.net] On Behalf Of Joe Abley Sent: Wednesday, September 09, 2009 01:37 To: cisco-nsp@puck.nether.net Subject: [c-nsp] small cisco as ethernet bridge, IPv6 broken, sadness I have the following setup in place for remote access to an exchange point in Toronto: juniper J2320 router | cisco bridge 1 | | ) telco-provided -------|------- ) layer-2 | ) transport | cisco bridge 2 | exchange point | peer router The telco transport in question is DSL at the top and ethernet at the bottom. The top bridge is connecting local ethernet to ethernet over ATM over whatever, so it's a glorified DSL modem; the bottom bridge is there to clean the traffic that would otherwise flood to the exchange (e.g. to eliminate other weird, foreign-sourced frames that seem to appear from the telco layer-2 service from time to time). For IPv4, this all works gloriously. For IPv6, not at all. The bridges are both cisco 2600 devices with "no ip routing". Some config fragments below. The top bridge has a DSL WIC and I'm bridging between that and a VLAN configured on an FE port; the bottom bridge has a pair of FE ports, and I'm bridging between them with no VLANs. There is a single BVI configured on "cisco bridge 2" just to give me an address to ssh to. I tried removing that and managing the box via the console, but no change. Is there something fundamental I'm missing, here? Why should a transparent bridge behave differently with IPv4 than it does with IPv6? Joe ! cisco bridge 1 cisco 2620 (MPC860) processor (revision 0x102) with 61440K/4096K bytes of memory. System image file is "flash:c2600-ik9o3s3-mz.123-26.bin" interface ATM0/0 no ip address no ip route-cache no atm ilmi-keepalive dsl operating-mode auto ! interface ATM0/0.1 point-to-point no ip route-cache bridge-group 1 pvc 0/35 encapsulation aal5snap ! ! interface FastEthernet0/0.200 encapsulation dot1Q 200 no ip route-cache bridge-group 1 bridge-group 1 spanning-disabled ! bridge 1 protocol ieee ! cisco bridge 2 cisco 2621 (MPC860) processor (revision 0x102) with 61440K/4096K bytes of memory. System image file is "flash:c2600-ik9o3s3-mz.123-26.bin" interface FastEthernet0/0 description facing the telco speed 100 full-duplex bridge-group 1 bridge-group 1 spanning-disabled ! interface FastEthernet0/1 description facing the exchange point bridge-group 1 bridge-group 1 output-pattern-list 1100 bridge-group 1 spanning-disabled ! interface BVI1 description a way to manage the bridge, v4-only is fine ip address x.x.x.x y.y.y.y ! bridge 1 protocol ieee bridge 1 route ip _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/