Thank you for this. The commit has more info than the TCP manual, which seemed to only allow for this to be boolean (1 or 0). I see that “2” applies to loopback only, which is interesting.
I thought maybe VyOS was setting this somewhere in runtime, since it was absent from sysctl.conf, but now I see in the diff that “2” is the default:
index 924bd51327b7..6841c74eac00 100644
--- a/[Documentation/networking/ip-sysctl.txt](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/ip-sysctl.txt?id=39dbc646fd2c67ee9b71450ce172cbd714d4e7fb)
+++ b/[Documentation/networking/ip-sysctl.txt](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/ip-sysctl.txt?id=79e9fed460385a3d8ba0b5782e9e74405cb199b1)
@@ -667,11 +667,15 @@ tcp_tso_win_divisor - INTEGER
building larger TSO frames.
Default: 3
-tcp_tw_reuse - BOOLEAN
- Allow to reuse TIME-WAIT sockets for new connections when it is
- safe from protocol viewpoint. Default value is 0.
+tcp_tw_reuse - INTEGER
+ Enable reuse of TIME-WAIT sockets for new connections when it is
+ safe from protocol viewpoint.
+ 0 - disable
+ 1 - global enable
+ 2 - enable for loopback traffic only
It should not be changed without advice/request of technical
experts.
+ Default: 2```
Much appreciated!