Wireshark · Ethereal-users: Re: [Ethereal-users] 802.1Q and capture filters

[Guy Harris <guy@xxxxxxxxxx>]

On Fri, Aug 09, 2002 at 06:47:55AM -0500, McNutt, Justin M. wrote:
> Ideas?

Libpcap bug?  "vlan" temporarily modifies some internal variables in
libpcap's code generator so that subsequent tests realize that packets
are VLAN-encapsulated - but that shouldn't persist from expression to
expression.

A problem like that wouldn't show up in tcpdump (or Tethereal), as those
programs only parse one capture filter expression each time you run
them; Ethereal often catches problems such as that, as it *can* compile
more than one capture filter expression.