Reading the linux-netdev archives ( http://marc.info/?l=linux-
netdevm=124836694205107w=2 );
ISC dhcp3d [sic] does not use libpcap, and does not query the packet
socket for the VLAN tag, so it treats every VLAN's packets as for the
default VLAN..
This is just as the OP describes. So unless the
DistroRelease: Ubuntu 9.10
Package: dhcp3-server 3.1.2-1ubuntu7.1
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 2.6.31-19.56-server
I can confirm that even with the recent configuration above any DHCP
requests that come over a tagged VLAN are also seen by the untagged
interface. Here
