On Wed, 4 Sep 2024 08:24:07 +0200, Gert Doering wrote ... > So how does MacOS deal with intermediate routers that can only handle > 1492? This is a very common scenario for PPPoE-based DSL connections, > and since it's not "a local interface" it would have to handle the > ICMPs somehow. > > I know that Linux can directly return the ICMP errors to the userland > socket (which no other platform supports, alas) - but Linux will also > put "packet too big" ICMPs into a route cache, so the next sendto() > call can do the fragmentation / EMSGSIZE return right away, not > having to wait for the incoming ICMP packet. Doesn't MacOS has a > comparable mechanism?
It does, but it seems to be implemented only in TCP driver. Thus UDP/RAW sockets can't use ICMP Fragmentation needed. IIRC, the same limitation was in the past on BSD Unix, not sure what's the current status. With kind regards, MD _______________________________________________ Openvpn-users mailing list Openvpn-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openvpn-users
