====== NFTables ======
Example from eric with combined ipv4+ipv6 (latter untested): https://github.com/ericwoud/buildR64arch/blob/main/rootfs/etc/nftables.conf
forwarding: https://www.eukhost.com/kb/how-to-enable-ip-forwarding-on-linux-ipv4-ipv6/
apt install nftables
echo 1 > /proc/sys/net/ipv4/ip_forward
nft list ruleset
nft add table nat
nft add chain ip nat prerouting { type nat hook prerouting priority 100 \; }
nft add chain ip nat postrouting { type nat hook postrouting priority 100 \; }
nft add rule nat postrouting masquerade
#portforwarding
nft add rule nat prerouting iif lan1 tcp dport 443 dnat 192.168.0.10:443 # ip needs to be routed to other interface then in-interface (here lan1)
named priorities (>=0.9.1): https://thermalcircle.de/doku.php?id=blog:linux:nftables_packet_flow_netfilter_hooks_detail
===== links =====
* https://developers.redhat.com/blog/2017/01/10/migrating-my-iptables-setup-to-nftables/
* https://wiki.gentoo.org/wiki/Nftables/Examples#Basic_routing_firewall
* https://wiki.nftables.org/wiki-nftables/index.php
* https://wiki.nftables.org/wiki-nftables/index.php/Quick_reference-nftables_in_10_minutes
===== hwnat =====
https://github.com/frank-w/BPI-R2-4.14/commits/5.12-hnat
ipv6 mangle does not support hnat (connection reset!)
to get hwnat working, a newer version of nftables is needed than available in debian buster
https://github.com/frank-w/nftables-bpi
compiled: https://drive.google.com/drive/folders/1hajKvqQa96WRrAy52fQX90i59I1s0h-i?usp=sharing
basic IPv4 Ruleset:
flush ruleset
table ip filter {
flowtable f {
hook ingress priority filter + 1
devices = { lan3, lan0, wan }
flags offload;
}
chain input {
type filter hook input priority filter; policy accept;
}
chain output {
type filter hook output priority filter; policy accept;
}
chain forward {
type filter hook forward priority filter; policy accept;
ip protocol { tcp, udp } flow add @f
}
}
table ip nat {
chain post {
type nat hook postrouting priority filter; policy accept;
oifname "wan" masquerade
}
chain pre {
type nat hook prerouting priority filter; policy accept;
}
}
basic v6 Ruleset (hw-nat for IPv6 not supported):
flush ruleset
table ip6 filter {
flowtable f {
hook ingress priority 1
devices = { lan3, lan0, wan }
flags offload;
}
chain input {
type filter hook input priority 0; policy accept;
}
chain output {
type filter hook output priority 0; policy accept;
}
chain forward {
type filter hook forward priority 0; policy accept;
# ip6 nexthdr { tcp, udp } flow add @f
}
}
table ip6 nat {
chain post {
type nat hook postrouting priority 0; policy accept;
#oifname "wan" masquerade
}
chain pre {
type nat hook prerouting priority 0; policy accept;
}
}
test it:
nft -f nft-nat-flowoffload.nft
#generate traffic from client e.g. iperf3
cat /sys/kernel/debug/mtk_ppe/entries
IPV6-Setup
#!/bin/bash
#on main-router:
#ip -6 route add fd00:a2::/64 via fd00:a::12
#ip -6 route add 2001:470:xxxx:a2::/64 via 2001:470:xxxx::12
ip -6 addr add fd00:a::12/64 dev wan
ip -6 addr add fd00:a2::12/64 dev lan3
ip -6 addr add 2001:470:xxxx::12/64 dev wan
ip -6 addr add 2001:470:xxxx:a2::12/64 dev lan3
sysctl -w net.ipv6.conf.all.forwarding=1