diff options
| author | Jason McIntyre <jmc@cvs.openbsd.org> | 2005-07-17 19:15:39 +0000 |
|---|---|---|
| committer | Jason McIntyre <jmc@cvs.openbsd.org> | 2005-07-17 19:15:39 +0000 |
| commit | 8e358d6a694150760bba0cc81a436da4824658c6 (patch) | |
| tree | 6a8c2a0d66e8165de4487cf53752b9a8e66da1c5 /usr.bin | |
| parent | 2fb59ec8306d018a5127d01260b0d3068f8221e8 (diff) | |
some improvements from alf schlichting:
- correct syntax for retrieving an http page. this example further
corrected by ian darwin (thanks!)
- the -v flag is relatively useless when port scanning, so remove it
from the example, and reword the description appropriately
- udp port scans always report ports as open (i.e. are useless) so
remove example claiming it works, and add CAVEATS to note that -uz is
relatively useless
Diffstat (limited to 'usr.bin')
| -rw-r--r-- | usr.bin/nc/nc.1 | 25 |
1 files changed, 11 insertions, 14 deletions
diff --git a/usr.bin/nc/nc.1 b/usr.bin/nc/nc.1 index c82e6efe4ab..19dcad5d5fb 100644 --- a/usr.bin/nc/nc.1 +++ b/usr.bin/nc/nc.1 @@ -1,4 +1,4 @@ -.\" $OpenBSD: nc.1,v 1.38 2005/05/20 10:55:09 jmc Exp $ +.\" $OpenBSD: nc.1,v 1.39 2005/07/17 19:15:38 jmc Exp $ .\" .\" Copyright (c) 1996 David Sacerdote .\" All rights reserved. @@ -291,7 +291,7 @@ when it might be necessary to verify what data a server is sending in response to commands issued by the client. For example, to retrieve the home page of a web site: .Pp -.Dl $ echo \&"GET\&" | nc host.example.com 80 +.Dl $ echo -n \&"GET / HTTP/1.0\er\en\er\en\&" | nc host.example.com 80 .Pp Note that this also displays the headers sent by the web server. They can be filtered, using a tool such as @@ -319,15 +319,11 @@ The .Fl z flag can be used to tell .Nm -not to initiate a connection, -together with the -.Fl v -.Pq verbose -flag, -to report open ports. +to report open ports, +rather than initiate a connection. For example: .Bd -literal -offset indent -$ nc -vz host.example.com 20-30 +$ nc -z host.example.com 20-30 Connection to host.example.com 22 port [tcp/ssh] succeeded! Connection to host.example.com 25 port [tcp/smtp] succeeded! .Ed @@ -365,11 +361,6 @@ IP for the local end of the connection: .Pp .Dl $ nc -s 10.1.2.3 host.example.com 42 .Pp -Send UDP packets to ports 20-30 of host.example.com, and report which ones -responded with an ICMP packet after three seconds: -.Pp -.Dl $ nc -uvz -w 3 host.example.com 20-30 -.Pp Create and listen on a Unix Domain Socket: .Pp .Dl $ nc -lU /var/tmp/dsocket @@ -394,3 +385,9 @@ Original implementation by *Hobbit* .br Rewritten with IPv6 support by .An Eric Jackson Aq ericj@monkey.org . +.Sh CAVEATS +UDP port scans will always succeed +(i.e. report the port as open), +rendering the +.Fl uz +combination of flags relatively useless. |