[j-nsp] M7i DHCP Relay

[sthaug at nethelp.no]

> I am trying to get DHCP relay working using either [forwarding-options 
> dhcp-relay] or [forwarding-options helpers bootp] on an M7i w/IQ2 
> ethernet running 9.6R1.13.  I have several double-tagged and single 
> tagged vlans on interface ge-0/0/3 and am wanting to do relay on several 
> double-tagged units that are unnumbered to lo0.0.  The bootp helper 
> doesn't seem to forward/relay any requests if the interface is 
> unnumbered - it works fine if the interface has an IP.  DHCP-relay seems 
> to effect all of the units on ge-0/0/3 even though I only specify a 
> certain unit to operate on.

Yes. This is a serious bug which basically makes M/MX routers unusable
if you want to have DHCP relay agent functionality *on the router* at
the same time as you have other DHCP unicast traffic (for instance
generated by a Cisco CPE with "ip helper", or a client sending its
renewal request directly to the DHCP server) passing *through* the
router.

I find it absolutely incredible that Juniper with its ERX history has
managed to botch the M/MX DHCP functionality this badly.

Verified with 9.5R4.3 and 10.0R2.10.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no