DHCP and multiple vlans

[Sten Daniel Sørsdal]

> I'm trying to configure a FreeBSD 5.1-RELEASE system to act 
> as the default gateway for several virtual lans.  I've got 
> two NICs in the box, one which supplies the uplink, and one 
> which has about 40 vlan(4) vlans on it.
> 
> I was trying to run isc-dhcp3's dhcrelay to relay DHCP 
> messages to our DHCP server when I ran into a problem.  Only 
> the first ten vlans (vlan0 through
> vlan9) are serviced by dhcrelay.
> 

It's a limitation in the isc-dhcp software, AFAIK.
If my memory serves me correctly you can try something along these lines;

# cd /usr/ports/net/isc-dhcp3-server
# make patch
now edit work/dhcp-3.0.1rc12/common/discover.c
at line 138 or so there should be "char buf[2048]"
change 2048 into for example 16384.
# make build install
assuming you are building on your gateway.

_// Sten Daniel Sørsdal