Subject: Re: bin/34733
To: None <gnats-admin@netbsd.org, netbsd-bugs@netbsd.org,>
From: Brian A. Seklecki <bseklecki@collaborativefusion.com>
List: netbsd-bugs
Date: 12/19/2006 20:15:05
The following reply was made to PR bin/34733; it has been noted by GNATS.
From: "Brian A. Seklecki" <bseklecki@collaborativefusion.com>
To: gnats-bugs@NetBSD.org
Cc: gnats-admin@netbsd.org, netbsd-bugs@netbsd.org
Subject: Re: bin/34733
Date: Tue, 19 Dec 2006 15:12:14 -0500
Right; this is on a profiled system w/ :
mk.conf(5)
USE_INET6=no
MKINET6=no
NO_INET6=yes
So the problem only surfaces because the 96byte Snaplen is required for
both IPv6 _and_ CARP, and since CARP can work in IPv4-only environments,
it is a rare bug, but almost certainly warrants either:
-) run-time instead of compile-time checks
-) changing the default snaplen globally
...which doesn't seem like it'll have an detrimental performance impact
other than extremely high volume ipv4-only sites (which are probably
using libpcap/tcpdump from pkgsrc anyway)
~BAS
>
> src/dist/tcpdump/interface.h has:
>
> /*
> * The default snapshot length. This value allows most printers to print
> * useful information while keeping the amount of unwanted data down.
> */
> #ifndef INET6
> #define DEFAULT_SNAPLEN 68 /* ether + IPv4 + TCP + 14 */
> #else
> #define DEFAULT_SNAPLEN 96 /* ether + IPv6 + TCP + 22 */
> #endif
>
> I wonder where the problem is.
> INET6 is defined in src/usr.sbin/tcpdump/Makefile
>
> Do you have USE_INET6=no??
>
>
>
>
>
>
>
--
Brian A. Seklecki <bseklecki@collaborativefusion.com>
Collaborative Fusion, Inc.