DHCP w/ FHRP and duplicate requests

Arran Cudbard-Bell a.cudbardb at freeradius.org
Wed Mar 12 12:41:31 CET 2014

On 12 Mar 2014, at 11:24, Phil Mayers <p.mayers at IMPERIAL.AC.UK> wrote:

> All,
> I haven't had the chance to try FR DHCP yet, but I ran into a problem with ISC yesterday and I thought I'd mention something worth considering.
> If you have something like VRRP/HSRP for first-hop resilience, both routers will forward the DHCP packet, and you'll get two copies that differ only in giaddr, very close together in time.
> For fixed IPs this isn't usually a problem, but if you're allocating a lease by DB lookup, I guess it would be possible for 2 DISCOVERs to get 2 different OFFERs, particularly if you're threaded.
> I'm wondering if the radius "duplicate packet detection" code could be re-used here?
> It seems like rlm_cache would probably run "too late"?

Why do you think it would be run too late?

Arran Cudbard-Bell <a.cudbardb at freeradius.org>
FreeRADIUS Development Team

FD31 3077 42EC 7FCD 32FE 5EE2 56CF 27F9 30A8 CAA2

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 881 bytes
Desc: Message signed with OpenPGP using GPGMail
URL: <http://lists.freeradius.org/pipermail/freeradius-devel/attachments/20140312/94b0b450/attachment.pgp>

More information about the Freeradius-Devel mailing list