Hello, I think a found a typo in the wiki pages of nftables. https://wiki.nftables.org/wiki-nftables/index.php/Mangle_TCP_options mentioned the following command: nft add rule ip filter forward oifname ppp0 tcp flags syn tcp option maxseg size set rt mtu But this didn't solved my problem. In the release notes: http://lists.netfilter.org/pipermail/netfilter-announce/2017/000225.html mentioned the following command: nft add rule mangle forward tcp flags syn tcp option maxseg size set rt mtu and this works. Logical, because now it is in the right table. Best Regards, Pieter
