On Wed, May 13, 2020 at 02:17:41PM +0100, David Howells wrote: > Christoph Hellwig <hch@xxxxxx> wrote: > > > + ip_sock_set_mtu_discover(conn->params.local->socket->sk, > > + IP_PMTUDISC_DONT); > > Um... The socket in question could be an AF_INET6 socket, not an AF_INET4 > socket - I presume it will work in that case. If so: Yes, the implementation of that sockopt, including the inet_sock structure where these options are set is shared between ipv4 and ipv6.