reassemble large packets in switch mode

[Axel Christiansen]

Hello,


i run into trouble using tinc in switch mode.
Its a simple setup with 2 hosts.

Both running tincd 1.0.4 (Debian testing)

Setup host A:

Server, does not make connections to host
B. The vpn0 interface is part of a Linux bridge,
witch is ipv4 configured.

Setup host B:

Makes connections to host
A, beside this its configured similar.



Now it seems large packets can not be transmitted.
I verified it step by step the way with tcpdump.
A ping with a size larger then 1400 byte gets not
reassembled in the tincd on host B, no matter witch
side i use.

On host A i see the fragmented udp packets arrive,
assembled to a large ping and show up on the bridge
interface. Then those pings gets answered and find
there way back to host B nicely. They arrive on host
B as udp fragments but then dont show up in the bridge.

So it seems host B disassembles the packets to udp
but not reassembles them. At least i can see the pings.

By the way, it seems the PMTU setting has no affect. I lowered
the MTU size to 1400, but udp fragments still have a size
of 1524.


Any ideas? Thanks, Axel