Ping across auto IPV6 Tunnel - 50%

Hey team,

Got this working tonight, auto ipv6 tunnels.

Divin provided me this link:
http://ardenpackeer.com/routing-protocols/tutorial-ipv6-tunnels-part-2-automatic-6to4-tunnels/
<-- this helped me much.

Conceptually it helped me to consider this a 'hack' or 'cheat'. Kind of
neat in some ways too I guess ... by defining the IPv4 address as part of
the IPv6 address, you are really telling the router to find the remote peer
by it's IPv4 address. Of course ... the IPv4 routing table needs to be
right before this will work ...

Any who ... my question is related to ping. Has anyone else seen 50% ping
timeout when using auto tunnels? I get all responses to other frame relay
ipv6 peers or Ethernet peers etc ... . Here is the output, kind of looks
like a pacing issue, but the fact that other pings work 100% of the time
does not make sense.

R1(config)#do ping 2001:3:3:3::3 sou 2001:1:1:1::1 re 10

Sending 10, 100-byte ICMP Echos to 2001:3:3:3::3, timeout is 2 seconds:
Packet sent with a source address of 2001:1:1:1::1
!.!.!.!.!.
Success rate is 50 percent (5/10), round-trip min/avg/max = 32/32/36 ms

I have static routes going to the remote tunnel peer.

Trace works just fine, no timeouts, single hop. I tried it with and without
ipv6 cef. I also did a debug ipv6 pack det and debug ipv6 icmp ... nothing
out of the ordinary ...

Any thoughts? Seen this?

-- 
Andrew Lee Lissitz
all.from.nj_at_gmail.com
Blogs and organic groups at http://www.ccie.net