GroupStudy.com GroupStudy.com - A virtual community of network engineers
 Home  BookStore  StudyNotes  Links  Archives  StudyRooms  HelpWanted  Discounts  Login
Re: DHCP snooping setup posted 02/16/2007
[Chronological Index] [Thread Index] [Top] [Date Prev][Date Next] [Thread Prev][Thread Next]


The trust command

On 2/16/07, Jian Gu <guxiaojian@xxxxxxxxx> wrote:
>
> This was asked before, there is a interface command which will allow DHCP
> packets with option 82 to go through in stead of drop them.
>
> On 2/16/07, Filyurin, Yan <yan.filyurin@xxxxxxx> wrote:
> >
> > Hello list.  I was recently playing around with DHCP snooping
> > configuration
> > and they way I had it set up was that I had router A and B connected to
> a
> > switch being on the same vlan where A was getting its IP address from B
> > through DHCP.  So I decided to play with DHCP snooping and enabled it
> for
> > that
> > particular vlan.  Suddenly DHCP stopped working.  After doing a couple
> of
> > debugs, I could see that A was originating the request and B was seeing
> it
> > and
> > giving an error, and the only way I could resolve it is by doing:
> >
> > no ip dhcp snooping information option
> > And ip dhcp snooping trust
> > After reading RFC that kind of makes sense and of course the second
> makes
> > sense on the router port.  The question is.  If I had router C
> (somewhere
> > behind router B) set up as a DHCP server and router B would just be a
> > relay
> > with the helper-address command, would I still need to do this tweak
> > because
> > it appeared that router B was getting confused by the switch setting
> > option
> > 82.
> >
> > Thank you
> >
> >
> >
> >
> > Yan Filyurin
> > EDS - Bank of America, Network Design
> > MS: MA6-536-0501
> > 1025 Main Street
> > Waltham, MA  02451
> > Office: +1-781-788-2207
> > Cell: +1-617-875-4862
> > yan.filyurin@xxxxxxx
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>



-- 
Narbik Kocharians
CCIE# 12410 (R&S, SP, Security)
CCSI# 30832
Network Learning, Inc. (CCIE class Instructor)
www.ccbootcamp.com (CCIE Training)