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authorxu xin <xu.xin16@zte.com.cn>2021-12-30 06:28:56 +0300
committerDavid S. Miller <davem@davemloft.net>2021-12-30 16:28:04 +0300
commitbe1c5b53227ba8280f1ebb01c6f5da3c9eebdaad (patch)
tree950702710e8c58a71e859d0110c5408b359d94ca /Documentation/networking/ip-sysctl.rst
parentccc0c9be75cf27f415d50fecf1a57b650defe39d (diff)
downloadlinux-be1c5b53227ba8280f1ebb01c6f5da3c9eebdaad.tar.xz
Documentation: fix outdated interpretation of ip_no_pmtu_disc
The updating way of pmtu has changed, but documentation is still in the old way. So this patch updates the interpretation of ip_no_pmtu_disc and min_pmtu. See commit 28d35bcdd3925 ("net: ipv4: don't let PMTU updates increase route MTU") Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: xu xin <xu.xin16@zte.com.cn> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking/ip-sysctl.rst')
-rw-r--r--Documentation/networking/ip-sysctl.rst6
1 files changed, 4 insertions, 2 deletions
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index c04431144f7a..2572eecc3e86 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -25,7 +25,8 @@ ip_default_ttl - INTEGER
ip_no_pmtu_disc - INTEGER
Disable Path MTU Discovery. If enabled in mode 1 and a
fragmentation-required ICMP is received, the PMTU to this
- destination will be set to min_pmtu (see below). You will need
+ destination will be set to the smallest of the old MTU to
+ this destination and min_pmtu (see below). You will need
to raise min_pmtu to the smallest interface MTU on your system
manually if you want to avoid locally generated fragments.
@@ -49,7 +50,8 @@ ip_no_pmtu_disc - INTEGER
Default: FALSE
min_pmtu - INTEGER
- default 552 - minimum discovered Path MTU
+ default 552 - minimum Path MTU. Unless this is changed mannually,
+ each cached pmtu will never be lower than this setting.
ip_forward_use_pmtu - BOOLEAN
By default we don't trust protocol path MTUs while forwarding