diff options
Diffstat (limited to 'doc/source/manual')
| -rw-r--r-- | doc/source/manual/config.rst | 13 | ||||
| -rw-r--r-- | doc/source/manual/mtu.rst | 4 |
2 files changed, 4 insertions, 13 deletions
diff --git a/doc/source/manual/config.rst b/doc/source/manual/config.rst index 5a09c6c..9f7d50c 100644 --- a/doc/source/manual/config.rst +++ b/doc/source/manual/config.rst @@ -230,17 +230,8 @@ Example config: | ``pmtu yes|no|auto;`` - Enables or disables Path MTU detection for IPv4. If enabled, all packets are sent with DF set, and all - fragmentation happens on the sending host itself. If disabled, routers may fragment the packets themselves, - possibly leading to multiple fragmentation. In general, disabling this should not be necessary, but in some - networks ICMP MTU Too Big packets are lost, so PMTU detection doesn't work correctly. - - If possible, fastd's mtu setting should be adjusted so the packets aren't fragmented at all instead of - relying on this option. - - The default is auto, which uses the system default as specified in /proc/sys/net/ipv4/ip_no_pmtu_disc. - - The pmtu option is available on Linux platforms only. + Does nothing; the ``pmtu`` option is only supported for compatiblity + with older versions of fastd. | ``protocol "<protocol>";`` diff --git a/doc/source/manual/mtu.rst b/doc/source/manual/mtu.rst index 68731e0..804404d 100644 --- a/doc/source/manual/mtu.rst +++ b/doc/source/manual/mtu.rst @@ -2,8 +2,8 @@ MTU configuration ================= The default MTU of fastd is 1500. This allows briding the fastd interface in TAP mode with other interface with the same MTU, but will usually cause fastd's UDP -packets to be fragmented (see also the option :ref:`pmtu <option-pmtu>`). Fragmentation can lower the -performance or even cause connectivty problems when broken routers filter ICMP packets, +packets to be fragmented. Fragmentation can lower the +performance or even cause connectivity problems when broken routers filter ICMP packets, so if possible the MTU should be chosed small enough so that IP fragmentation can be avoided. Unlike OpenVPN, fastd doesn't support fragmentation itself, but relies on the IP stack to fragment packets when necessary. |