Speed issue in only one direction

[Florent Bautista]

More informations :

root at node1:~# tinc -n coppint info node2
Node:         sllm2
Address:      192.168.0.202 port 655
Online since: 2013-12-17 17:08:24
Status:       validkey visited reachable sptps udp_confirmed
Options:      pmtu_discovery clamp_mss
Protocol:     17.3
Reachability: directly with UDP
PMTU:         1451
Edges:        node1
Subnets:      xx:xx:xx:xx:xx:xx

root at node2:~# tinc -n coppint info node1
Node:         sllm1
Address:      192.168.0.200 port 655
Online since: 2013-12-17 17:08:24
Status:       validkey visited reachable sptps udp_confirmed
Options:      pmtu_discovery clamp_mss
Protocol:     17.3
Reachability: directly with UDP
PMTU:         1518
Edges:        node2
Subnets:      xx:xx:xx:xx:xx:xx



Why PMTU is different ?? They are on a same switch, with same network
configuration (MTU 1500)...