[nsp] dsl/dhcp question

[Charles Sprickman]

Hi all,

A few more  questions on DHCP + RBE to take care of things while I get the
fancy option 82 business and ISC-DHCP playing nice together...

Looking at the RBE docs (which seem to have gotten slimmer since the 6400
was EOL'd), there are some examples like this:

http://www.cisco.com/warp/customer/794/827rfc_6400rbe_2.html

In this example, there is a 675 in bridge mode and a pc setup as a dhcp
client.  The pvc terminates on a 6400, but there is no dhcp config on the
6400; just a static route set to the pvc.  What gives?  Is this just a
mistake, or am I missing something?  From what I see, this wouldn't work.

Next...  With RBE and the IOS dhcp server, if I enable dhcp, does the
server (not relay-agent) automatically add a static route to the atm
subinterface for the duration of the lease?

Lastly, I've been trying to dig up as much info as I can on RBE and it
seems like there's less on CCO than I remember.  Should I be looking
anywhere beyond this:

http://www.cisco.com/cgi-bin/Support/browse/psp_view.pl?p=Internetworking:RBE__Route-Bridged_Encapsulation&viewall=true

I also was reading this, is there something like it that is updated?

http://www.cisco.com/warp/customer/794/routed_bridged_encap.html

Thanks,

Charles

On Mon, 30 Jun 2003, Siva Valliappan wrote:

> Hi Charles,
>
>    this is definitely possible.  you will need to enable option 82
> support on the router side.  what this does is that it fills in additional
> fields in the DHCP Discover packet that is proxied to the DHCP server.
> The server can then use the additional information to issue the same
> address if desired.  however, you will need to make changes to the
> DHCP server as well to make this happen.
>
> for the router overview:
>
> http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t2/ftrbeo82.htm
>
> this idea came from the cable world actually.  since the cable CMTSes were
> the first to make use of option 82 support to control the addresses given
> out to PCs behind cable modems.  so i believe any DHCP server that is
> used to provision cable modems, will support this.  e.g. CNR.  if you are
> using a Cisco DHCP server, a case with the TAC might help you get started.
>
> unfortunately i don't have a handy config sample for the DHCP server side.
> hope this helps you get started.
>
> cheers
> .siva
>
> On Sat, 28 Jun 2003, Charles Sprickman wrote:
>
> > Hello,
> >
> > I don't think the BBA list is big enough yet, so I thought I'd ask here.
> >
> > Some time ago when I first started looking at moving everyone from IRB to
> > RBE, I could have sworn I found a doc on CCO that had some nifty tricks
> > with RBE and DHCP.  Namely, that each user/subinterface could be tied to a
> > particular IP address.  ie: if a dhcp request came in on "atm 2/0.1999",
> > the dhcp server would always try to give out the same fixed IP.
> >
> > Did I imagine that?  I'm knee-deep in CCO and not seeing it.
> >
> > The goal is to auto-configure people who want static addresses without
> > knowing their mac address in advance.
> >
> > Anyone doing something similar and willing to share?  It looks like this
> > "option 82" thing can tell an external dhcp server something about where
> > the request came from, but I'm not sure which dhcp server support this.
> >
> > Thanks,
> >
> > Charles
> >
> > --
> > Charles Sprickman
> > spork at inch.com
> >
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>