diff options
Diffstat (limited to 'man7/tcp.7')
| -rw-r--r-- | man7/tcp.7 | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/man7/tcp.7 b/man7/tcp.7 index e28d088f4..221b20627 100644 --- a/man7/tcp.7 +++ b/man7/tcp.7 @@ -93,7 +93,7 @@ .\" commit cd8ae85299d54155702a56811b2e035e63064d3d .\" Author: Eric Dumazet <edumazet@google.com> .\" -.TH TCP 7 2020-06-09 "Linux" "Linux Programmer's Manual" +.TH TCP 7 2020-12-21 "Linux" "Linux Programmer's Manual" .SH NAME tcp \- TCP protocol .SH SYNOPSIS @@ -830,12 +830,11 @@ The maximum number of times a SYN/ACK segment for a passive TCP connection will be retransmitted. This number should not be higher than 255. .TP -.IR tcp_syncookies " (Boolean; since Linux 2.2)" +.IR tcp_syncookies " (integer; default: 1; since Linux 2.2)" .\" Since 2.1.43 Enable TCP syncookies. The kernel must be compiled with .BR CONFIG_SYN_COOKIES . -Send out syncookies when the syn backlog queue of a socket overflows. The syncookies feature attempts to protect a socket from a SYN flood attack. This should be used as a last resort, if at all. @@ -849,6 +848,18 @@ For recommended alternatives see .IR tcp_synack_retries , and .IR tcp_abort_on_overflow . +Set to one of the following values: +.RS +.IP 0 3 +Disable TCP syncookies. +.IP 1 +Send out syncookies when the syn backlog queue of a socket overflows. +.IP 2 +(since Linux 3.12) +.\" commit 5ad37d5deee1ff7150a2d0602370101de158ad86 +Send out syncookies unconditionally. +This can be useful for network testing. +.RE .TP .IR tcp_timestamps " (integer; default: 1; since Linux 2.2)" .\" Since 2.1.36 @@ -1393,7 +1404,7 @@ RFC\ 2581 for TCP congestion control algorithms. .br RFC\ 2018 and RFC\ 2883 for SACK and extensions to SACK. .SH COLOPHON -This page is part of release 5.09 of the Linux +This page is part of release 5.10 of the Linux .I man-pages project. A description of the project, |