From: ccie2be (ccie2be@nyc.rr.com)
Date: Mon Nov 29 2004 - 15:36:07 GMT-3
Thanks Bob.
I figured as much but just wanted to double check. I don't have access to a
3550 to confirm this.
----- Original Message -----
From: "Bob Smith" <ccnet101@nmccentral.com>
To: "ccie2be" <ccie2be@nyc.rr.com>; "Group Study" <ccielab@groupstudy.com>
Sent: Monday, November 29, 2004 1:17 PM
Subject: Re: DHCP and the 3550
> As long as the router/dhcp server is in the same VLAN, those hosts will
get
> a response, however, if its a different subnet or network, just remember
> helper address...
>
>
> ----- Original Message -----
> From: "ccie2be" <ccie2be@nyc.rr.com>
> To: "Group Study" <ccielab@groupstudy.com>
> Sent: Monday, November 29, 2004 10:00 AM
> Subject: DHCP and the 3550
>
>
> > Hi guys,
> >
> > I would like to just confirm something regarding the above.
> >
> > Assume a router's ethernet interface is connected to a 3550 port which
is
> > vlan
> > X along with a bunch of hosts.
> >
> > Also, the router is configured as dhcp server for the hosts in vlan X.
> >
> > Am I correct in thinking that nothing related to dhcp must be configured
> > on
> > the 3550?
> >
> > The way I understand it, when a host in vlan X powers up and sees it
needs
> > an
> > ip address, it will broadcast a dhcp request. The 3550, when it gets
that
> > broadcast, will flood the broadcast out all ports in vlan X. Thus, the
> > router
> > acting as a dhcp server will get the broadcast dhcp request. After
> > getting
> > the request, the router will respond using the source mac address of the
> > request as the destination mac address.
> >
> > When the 3550 gets the response, it will forward it to the host.
> >
> > In other words, the default behavior of the 3550 is such that nothing
> > related
> > to dhcp (such as dhcp snooping, dhcp relay, etc) is required for dhcp to
> > work
> > properly in the above scenario.
> >
> > I'd hate to lose points for dhcp on the lab if I correctly configure it
on
> > the
> > router and forget to configure some stupid little thing on the 3550.
> >
> > TIA, Tim
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Thu Dec 02 2004 - 06:57:51 GMT-3