Tunnel stops during my forum page loads - any idea?

[dcottle]

Had my tunnel up and it works good but it stops and stalls on my forum.

I don't know does not happen on ipv4, just on ipv6.

All my other websites are okay. But my forum has a lot of images, and it's always stalling on ipv6. It just loads up and some images load fully, other just stop. You have to hit stop on firefox or it just loads forever.

Sometimes when I reply, it just sits and sits. But if I check on the ipv4 the post / reply has been made.

Any idea's it's just dismal. Smaller sites on my server are fine. It's either too many images and it just stops. Once every so often I get a complete page load.

[antillie]

Maybe an MTU issue? Maybe try setting your IPv6 MTU to 1280? Your not filtering ICMPv6 are you?

[dcottle]

Is there a way to test the MTU reliably?

No filtering I can ping6 and get replies.

Also I am using two tunnels.  One for the server and one for my LAN.

I don't have issues with any other sites, just mine, but it is tunnel to tunnel..

According to ifconfig its running mtu of 1480

It just seems totally unstable. One minute a ping6 -c4 -s 2000 works, next it does not and complains it can't be bigger than 1472! Why 1472, should be 1480 as I am PPPoA

This is the whole issue, it's so flakey, works great then hopeless and no reason.

I don't have any mtu set in the sit1 in network-scripts or radvd.conf

I just set in my ifcfg-sit1 IPV6_MTU="1472" since it complains this randomly in ping6

But a ifconfig still shows it's set to 1480 not 1472! I did an ifdown sit1 and ifup sit1 still reports 1480 mtu

Why?