RESOLVED: Weird IPv6 problem passing Layer3 traffic

[Matthew Huff]

The issue was a CoPP filter on the ISP side. The session is up now. 

Been working on them with them for 3 days, and each engineer kept coming back to our BGP configuration. 

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Matthew Huff             | 1 Manhattanville Rd
Director of Operations   | Purchase, NY 10577
OTA Management LLC       | Phone: 914-460-4039


> -----Original Message-----
> From: Matthew Huff
> Sent: Friday, June 28, 2013 10:34 AM
> To: 'cisco-nsp (cisco-nsp at puck.nether.net)'; 'ipv6-ops at lists.cluenet.de'
> Subject: Weird IPv6 problem passing Layer3 traffic
> 
> Trying to bring up a new BGP peering session with a ISP. IPv4 peering is working fine on the same
> interface. The BGP peering fails early in trying to go active. Using "debug tcp transactions", I see
> the SYN going out, but no ACK ever returning. I can't telnet to their box on port 179 either (debug
> packet shows it doing the same, SYN begin sent, but no packets, including ACK). However, I can ping
> their interface.
> 
> The interface config has been stripped, and still doesn't work. I've reset the interface, and even
> rebooted our router, with no change in behavior.
> 
> We have a Cisco 7204VXR with NPE-G2, running 15.2(4)S1. I have an identical router with same version
> connected to another ISP and a tunnel to HE.net. It's not my first time at the rodeo. We are connected
> via metro Ethernet to a sub-interface on a JunOS box (model and version unknown). My suspicion is that
> either they have an ACL that's blocking it, or their BGP process isn't listening on that sub-
> interface. But they claim that it isn't their problem. I have zero JunOS experience and they seem to
> be flopping around.
> 
> Anyone have any idea what else the problem might be?
> 
> From our side (simplied config to test):
> 
> 
> interface FastEthernet2/1
>  ip address 162.211.110.2 255.255.255.252
>  speed auto
>  duplex auto
>  ipv6 address 2607:F518:15F::2/126
>  ipv6 enable
> end
> 
> rtr-inet2#show ipv6 cef 2607:F518:15F::1
> 2607:F518:15F::1/128
>   attached to FastEthernet2/1
> 
> rtr-inet2#show ipv6 cef exact-route 2607:F518:15F::2 2607:F518:15F::1
> 2607:F518:15F::2 -> 2607:F518:15F::1 => IPV6 adj out of FastEthernet2/1, addr 2607:F518:15F::1
> 
> rtr-inet2#show ipv6 neighbors
> IPv6 Address                              Age Link-layer Addr State Interface
> 2607:F518:15F::1                            0 0021.5903.1367  REACH Fa2/1
> 
> rtr-inet2#ping  2607:F518:15F::1
> Type escape sequence to abort.
> Sending 5, 100-byte ICMP Echos to 2607:F518:15F::1, timeout is 2 seconds:
> !!!!!
> Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
> 
> ----
> Matthew Huff             | 1 Manhattanville Rd
> Director of Operations   | Purchase, NY 10577
> OTA Management LLC       | Phone: 914-460-4039