diff options
| -rw-r--r-- | share/man/man4/options.4 | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/share/man/man4/options.4 b/share/man/man4/options.4 index 7d0d12d32e8..1b52686e564 100644 --- a/share/man/man4/options.4 +++ b/share/man/man4/options.4 @@ -1,4 +1,4 @@ -.\" $OpenBSD: options.4,v 1.24 1998/11/17 23:10:13 aaron Exp $ +.\" $OpenBSD: options.4,v 1.25 1998/11/29 14:12:14 angelos Exp $ .\" $NetBSD: options.4,v 1.21 1997/06/25 03:13:00 thorpej Exp $ .\" .\" Copyright (c) 1998 Theo de Raadt @@ -598,6 +598,17 @@ one segment has been dropped per window, the transmission can continue without waiting for a retranmission timeout. This option cannot be used together with .Em TCP_SACK . +.It Cd option TCPCOOKIE +This causes the kernel to keep a list of "friendly" hosts, that is IP +addresses that have been verified to exist. TCP connections from these +addresses are allowed to proceed. Connections from other addresses +trigger a mechanism for determining whether those are "friendly". The +list of friendle addresses is controlled by the +.Em TCK_NFRIENDS +option, which is by default set to 16. Unfortunately, hosts behind a +some stateful packet-filtering firewalls are unverifiable due to the +nature of the mechanism and the filtering process, thus connections +from such hosts are not allowed to proceed. .It Cd option TCP_SACK Turns on selective acknowledgements. Additional information about segments already received can be transmitted back to the sender, |