diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2022-12-06 18:02:25 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2022-12-07 19:18:06 +0100 |
| commit | 84da9b6e335b7aa5bdcf1bd88c62daed5bdac889 (patch) | |
| tree | 850d029a6d89003503ca023ddeb84aecd1337642 /doc/statements.txt | |
| parent | 43fa81bd59f88abf425be84a48596a46f367f44b (diff) | |
doc: statements: fwd supports for sending packets via neighbouring layer
Document ability to forward packets through neighbour layer added in
30d45266bf38 ("expr: extend fwd statement to support address and family").
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'doc/statements.txt')
| -rw-r--r-- | doc/statements.txt | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/doc/statements.txt b/doc/statements.txt index 8076c21c..bda63bb3 100644 --- a/doc/statements.txt +++ b/doc/statements.txt @@ -683,7 +683,24 @@ The fwd statement is used to redirect a raw packet to another interface. It is only available in the netdev family ingress and egress hooks. It is similar to the dup statement except that no copy is made. +You can also specify the address of the next hop and the device to forward the +packet to. This updates the source and destination MAC address of the packet by +transmitting it through the neighboring layer. This also decrements the ttl +field of the IP packet. This provides a way to effectively bypass the classical +forwarding path, thus skipping the fib (forwarding information base) lookup. + +[verse] *fwd to* 'device' +*fwd* [*ip* | *ip6*] *to* 'address' *device* 'device' + +.Using the fwd statement +------------------------ +# redirect raw packet to device +netdev ingress fwd to "eth0" + +# forward packet to next hop 192.168.200.1 via eth0 device +netdev ingress ether saddr set fwd ip to 192.168.200.1 device "eth0" +----------------------------------- SET STATEMENT ~~~~~~~~~~~~~ |