[c-nsp] DHCP pools: how to assign priority

[Dmitry Cherkasov]

2006/5/11, David Prall <dcp at dcptech.com>:
> It because of the secondary addressing the router is only looking at the
> primary address to match.


Can't confirm that. I swapped primary and secondary addresses on the
interface and the situation remained the same. Then I got rid of
secondary address at all and ensured that both pools assume the same
default-router. Yet again some devices (e.g. my FreeBSD notebook)
easily get address from the dynamic block and static base which
contains implicitely their MACs is ignored.

One possible solution that I found is using manual assignment instead
of static. Every static host gets description in the running config
like:

ip dhcp pool Host
   host <ip-addr>
   hardware-address <mac-address>

It works, but updating the running config seems much less convenient..

>
> You can use the dhcp smart relay agent
> http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chap
> ter09186a00804412bf.html#wp1089419
>

I don't see how smart relay helps. It only provides sending responses
from a proper ip-address on interface. Yet it does not solve my
problem.


> But, you will need to make the secondary address the primary address so that
> it is used first.
>
> David
>
> --
> David C Prall dcp at dcptech.com http://dcp.dcptech.com
>
>
> > -----Original Message-----
> > From: cisco-nsp-bounces at puck.nether.net
> > [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of
> > Dmitry Cherkasov
> > Sent: Thursday, May 11, 2006 7:33 AM
> > To: cisco-nsp at puck.nether.net
> > Subject: [c-nsp] DHCP pools: how to assign priority
> >
> > I configure two dhcp pools, one dynamic and the other static (the base
> > is loaded from an external file). Is there a way to force cisco
> > provide dhcp-clients with leases from the static base if their MAC is
> > present there and fall back to dynamic only if a corresponding MAC is
> > absent in the static base?
> >
> > For example:
> >
> > ip dhcp pool Dynamic
> >  network 10.1.1.0 255.255.255.0
> >  ...
> > ip dhcp pool Static
> >  origin file tftp://tftp.local/static.db
> >  ...
> > interface FastEthernet0
> >  ...
> >  ip address 10.1.1.1 255.255.255.0
> >  ip address 172.16.1.1 255.255.255.0 secondary
> >  ...
> >
> > Now I see the following:
> >
> > Router#sh ip dhcp bin
> > Bindings from all pools not associated with VRF:
> > IP address          Client-ID/                    Lease
> > expiration        Type
> >                   Hardware address/
> >                   User name
> > 172.16.1.2/24        0080.c7bc.09c4          Infinite
> >        Static
> > 10.1.1.2             0080.c7bc.09c4          May 11 2006
> > 01:58 PM    Automatic
> >
> >
> > I.e. a client 0080.c7bc.09c4 that is present in the static base
> > obtains a lease from dynamic pool.
> >
> > --
> > Dmitry Cherkasov
> >
> > _______________________________________________
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> > https://puck.nether.net/mailman/listinfo/cisco-nsp
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> >
>
>


-- 
Dmitry Cherkasov