pMTU discovery

[Bernhard Schmidt]

On 08.06.2012 18:47, Bernhard Schmidt wrote:

> PEBKAC, I was just being stupid. Compiled fine, will test right away.

It basically works, but I think you are using the wrong MTU value. I'm 
currently in an IPv4-only non-MTU-challenged location. Cisco Anyconnect 
client connects with 1418 bytes MTU, openconnect with 1315. I'm not 
exactly sure what the difference between X-DTLS-MTU and D-CSTP-MTU is 
supposed to be, but the tunnel should be able to transport the larger value.

TCP_INFO rcv mss 1348, snd mss 1348, adv mss 1448, pmtu 1500
[...]
X-CSTP-MTU: 1315
X-DTLS-MTU: 1418
DTLS option X-DTLS-MTU : 1418

I'll try MTU challenged (DSL) and native IPv6 transport either tonight 
or during the weekend.

Bernhard