> > It's local system policy, how do I react to packets. If it doesn't > > violate the min/max limits for ipv6 packets it emits onto the internet > > I don't see this as something that can be seen as mandatory.
It does violate the max limit for ipv6 packets it emits onto the internet. You're not allowed to emit > 1280 mtu packets without also supporting pmtu. > > And if you *truly* do want to violate internet standards you can > indeed already achieve this behaviour by dropping incoming icmpv6 > packet too big errors (and there's lots of reasons why that is a bad > idea...). > > I'll repeat what I said previously: this is a userspace visible > regression in behaviour, of none or very questionable benefit. > > It results in TCP over IPv6 simply not working to destinations to > which your locked mtu is higher then the real path mtu. This is why > 'locked mtu' on IPv4 turns of the Don't Fragment bit - to allow > fragmentation at intermediate routers. There is no such thing in > IPv6. > There is no DF bit, and there is no router fragmentation - all ipv6 > fragmentation is supposed to happen at the source host. > This is why hosts must either use 1280 min guaranteed mtu or be > responsive to pmtu errors. Otherwise things simply don't work.
