Altering MTU in ICMPv6 packet too big message
Hi there,
we're having a buggy, closed source IPv6 router here, which keeps announcing a wrong MTU via ICMPv6 packet too big messages. Is there a way to modify the 1500 to a 1480 with a rule in the mangle table on the host that receives those broken messages? I think despite this one value, also the checksum would have to be recalculated.
Cheers, Linus
PS: the tcpmss-target extension is not enough, as I'm still having trouble with UDP packets.
Quoted 9 lines · Linus Lüssing
Hi there,
we're having a buggy, closed source IPv6 router here, which keeps announcing a wrong MTU via ICMPv6 packet too big messages. Is there a way to modify the 1500 to a 1480 with a rule in the mangle table on the host that receives those broken messages? I think despite this one value, also the checksum would have to be recalculated.
Quoted 4 lines
Cheers, Linus
PS: the tcpmss-target extension is not enough, as I'm still having trouble with UDP packets.
If someone more experienced does not have a cleaner solution... I've found setting fixed MTU on the NIC of each box plugged into such hardware to work nicely for all protocols. Generating the ICMP message at a box that works.
AYJ
Amos