Hi, I am not sure if there is a reason why ACK cannot be set for NETLINK_TCPDIAG. If it is settable, please apply following patch. thanks, - KK diff -ruN linux-2.5.68.org/net/ipv4/tcp_diag.c linux-2.5.68/net/ipv4/tcp_diag.c --- linux-2.5.68.org/net/ipv4/tcp_diag.c 2003-05-20 11:38:06.000000000 -0700 +++ linux-2.5.68/net/ipv4/tcp_diag.c 2003-05-20 11:39:48.000000000 -0700 @@ -609,7 +609,7 @@ if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) return; err = tcpdiag_rcv_msg(skb, nlh); - if (err) + if (err || nlh->nlmsg_flags & NLM_F_ACK) netlink_ack(skb, nlh, err); } } - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html