diff options
Diffstat (limited to 'usr.sbin/tcpdump/tcpdump.8')
| -rw-r--r-- | usr.sbin/tcpdump/tcpdump.8 | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/usr.sbin/tcpdump/tcpdump.8 b/usr.sbin/tcpdump/tcpdump.8 index f42801bf4a0..f40eafde937 100644 --- a/usr.sbin/tcpdump/tcpdump.8 +++ b/usr.sbin/tcpdump/tcpdump.8 @@ -1,4 +1,4 @@ -.\" $OpenBSD: tcpdump.8,v 1.37 2003/07/17 08:45:37 markus Exp $ +.\" $OpenBSD: tcpdump.8,v 1.38 2003/08/21 19:14:23 frantzen Exp $ .\" .\" Copyright (c) 1987, 1988, 1989, 1990, 1991, 1992, 1994, 1995, 1996 .\" The Regents of the University of California. All rights reserved. @@ -27,7 +27,7 @@ .Nd dump traffic on a network .Sh SYNOPSIS .Nm tcpdump -.Op Fl adeflnNOpqStvxX +.Op Fl adeflnNoOpqStvxX .Op Fl c Ar count .Op Fl F Ar file .Op Fl i Ar interface @@ -116,6 +116,12 @@ will print .Dq nic instead of .Dq nic.ddn.mil . +.It Fl o +Print a guess of the possible operating system(s) of hosts that sent TCP SYN +packets. +See +.Xr pf.os 5 +for a description of the passive operating system fingerprints. .It Fl O Do not run the packet-matching code optimizer. This is useful only if you suspect a bug in the optimizer. @@ -1214,7 +1220,7 @@ will be of much use to you. The general format of a tcp protocol line is: .Bd -ragged -offset indent .Ar src No \&> Ar dst : -.Ar flags data\&-seqno ack window urgent options +.Ar flags src\&-os data\&-seqno ack window urgent options .Ed .Pp .Ar src @@ -1241,6 +1247,10 @@ or or a single .Ql \&. .Pq no flags . +.Ar src\&-os +will list a guess of the source host's operating system if the +.Ar -o +command line flag was passed to tcpdump. .Ar data\&-seqno describes the portion of sequence space covered by the data in this packet (see example below). @@ -1932,6 +1942,7 @@ interrupt. .\" traffic(1C), nit(4P), .Xr pcap 3 , .Xr bpf 4 +.Xr pf.os 5 .Sh AUTHORS Van Jacobson .Pq van@ee.lbl.gov , |