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-rw-r--r--docs/routing/mss-clamp.rst13
1 files changed, 6 insertions, 7 deletions
diff --git a/docs/routing/mss-clamp.rst b/docs/routing/mss-clamp.rst
index a4edf1c6..3fdd1153 100644
--- a/docs/routing/mss-clamp.rst
+++ b/docs/routing/mss-clamp.rst
@@ -1,7 +1,8 @@
.. _routing-mss-clamp:
+################
TCP-MSS Clamping
-----------------
+################
As Internet wide PMTU discovery rarely works, we sometimes need to clamp
our TCP MSS value to a specific value. This is a field in the TCP
@@ -18,16 +19,15 @@ value for IPv4 and IPv6.
IPv4
-^^^^
+====
.. cfgcmd:: set firewall options interface <interface> adjust-mss <number-of-bytes>
Use this command to set the maximum segment size for IPv4 transit
packets on a specific interface (500-1460 bytes).
-
Example
-"""""""
+-------
Clamp outgoing MSS value in a TCP SYN packet to `1452` for `pppoe0` and
`1372`
@@ -39,16 +39,15 @@ for your WireGuard `wg02` tunnel.
set firewall options interface wg02 adjust-mss '1372'
IPv6
-^^^^^
+====
.. cfgcmd:: set firewall options interface <interface> adjust-mss6 <number-of-bytes>
Use this command to set the maximum segment size for IPv6 transit
packets on a specific interface (1280-1492 bytes).
-
Example
-"""""""
+-------
Clamp outgoing MSS value in a TCP SYN packet to `1280` for both `pppoe0` and
`wg02` interface.