Hi,
Not true. The fact that there are UDP packets running on a native LAN or VLAN
which happen to carry a payload which is considered BOOTP has nothing to do
with the LAN they are running on.
There are numerous ways to get a node on a VLAN. Easiest is to assign a port
to a VLAN. Then the host doesn't have to fiddle with VLAN tags and stuff. If
the port can't handle the VLAN tagging/untagging, you'll have to configure the
host to do so. You can do that by, on the native LAN, forging a DHCP reply
option or point it to a configuration file it can read, so it knows what tag
to use. Then he restarts the BOOTP procedure applying the tag he received, so
he does host configuration on the configured VLAN.
See, all depends on the equipment, network design and policy you have.
Back to the original question. Sure you should be able to see them. I bet
you're using a Windows platform and try to sniff. These cards and their
drivers are a pain. Frisbee in a Knoppix lifeCD or something and capture with
that. You'll see it. The devil is in the details here.
Thanx,
Jaap
Andreas Fink wrote:
I think dhcp always is untagged on ethernet by the standard as it
might tell you what vlan to use maybe. At least i had such issues when
trying to run a dhcp server on a cisco connected on vlan virtual
interfaces
Von meinem iPhone gesendet
Am 18.03.2008 um 21:08 schrieb wb <wsbcomm@xxxxxxxxxxxxx>:
hey folks,
[sorry for the double post, looks like i posted incorrectly the
first time.]
if i'm sniffing between a linksys router and a cisco swtich, and the
linksys is on a vlan, shouldn't i be able to see DHCP OFFERS &
REQUESTS that clients are getting from this linksys router? or does
vlan tagging hid them or something?
tia
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