Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 20 Feb 2002 11:45:56 -0800
From:      Benjamin Krueger <benjamin@macguire.net>
To:        Peter Brezny <peter@skyrunner.net>
Cc:        freebsd-questions@freebsd.org
Subject:   Re: snap length
Message-ID:  <20020220114556.A12253@rain.macguire.net>
In-Reply-To: <NEBBIGLHNDFEJMMIEGOOGEKOEIAA.peter@skyrunner.net>; from peter@skyrunner.net on Wed, Feb 20, 2002 at 11:24:00AM -0500
References:  <NEBBIGLHNDFEJMMIEGOOGEKOEIAA.peter@skyrunner.net>

next in thread | previous in thread | raw e-mail | index | archive | help
* Peter Brezny (peter@skyrunner.net) [020220 10:22]:
> What is snap lenght?
> 
> In watching a tcp dump between a smb client/server, i keep seeing:
> 
> >>> NBT UDP PACKET(138) Res=0x1102 ID=0x34 IP=172 (0xac).18 (0x12).2
> (0x2).107 (0x6b) Port=138 (0x8a) Length=216
> (0xd8) Res2=0x0
> SourceName=NOC LAP 1       NameType=0x00 (Workstation)
> DestName=
> WARNING: Short packet. Try increasing the snap length

Peter,

Snap should be short for snapshot, which is the length of the packet that
tcpdump will capture for analysis and display to you. If the size of the
packet is larger than the default snap length, you will recieve the above
warning. From the tcpdump(1) manpage:

       -s     Snarf snaplen bytes of data from each packet rather
			        than the default of 68 (with SunOS's NIT, the mini-
							mum  is actually 96).  68 bytes is adequate for IP,
							ICMP, TCP and UDP but may truncate protocol  infor-
              ...

-- 
Benjamin Krueger

"From the moment I picked up your book until I laid it down, I 
was convulsed with laughter. Some day I intend reading it."
- Groucho Marx
----------------------------------------------------------------
Send mail w/ subject 'send public key' or query for (0x251A4B18)
Fingerprint = A642 F299 C1C1 C828 F186  A851 CFF0 7711 251A 4B18

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020220114556.A12253>