diff options
| author | Florian Westphal <fw@strlen.de> | 2019-07-21 12:43:05 +0200 |
|---|---|---|
| committer | Florian Westphal <fw@strlen.de> | 2019-07-22 11:39:29 +0200 |
| commit | 47a81d90a780269710266c2669388fb827ee5a0e (patch) | |
| tree | a68b9ed5b5c8a7b12c86fb1c5aed7ca4225fde70 /doc | |
| parent | 1b29e369e88f32c4275141d9c5ab3652e56a5387 (diff) | |
doc: fib: explain example in more detail
As noted by Felix Dreissig, fib documentation is quite terse, so explain
the 'saddr . iif' example with a few more words.
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1220
Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/primary-expression.txt | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/doc/primary-expression.txt b/doc/primary-expression.txt index 6eb9583a..34bcf2d3 100644 --- a/doc/primary-expression.txt +++ b/doc/primary-expression.txt @@ -274,6 +274,12 @@ fib_addrtype # drop packets without a reverse path filter prerouting fib saddr . iif oif missing drop +In this example, 'saddr . iif' looks up routing information based on the source address and the input interface. +oif picks the output interface index from the routing information. +If no route was found for the source address/input interface combination, the output interface index is zero. +In case the input interface is specified as part of the input key, the output interface index is always the same as the input interface index or zero. +If only 'saddr oif' is given, then oif can be any interface index or zero. + # drop packets to address not configured on ininterface filter prerouting fib daddr . iif type != { local, broadcast, multicast } drop |