Re: 4000M DHCP Traffic Blocking.

danbricker@xxxxxxxxx wrote:
I have a large network between 2 sister businesses that are located
next to each other. We are connected together with a fiber
connection to share resources and costs. We have seperate routers
and DHCP servers with different firewall rules. The problem we are
having is that when a DHCP client plugs into the network it is a
toss up as to which DHCP server will answer the clients request the
fastest. I have a HP procurve 4000m switch. Is there any way to
configure my Fiber port to not pass DHCP no matter which way it is
coming from. This would solve our problem but I have been unable to
find a way to make it work.

I think it would be more accurate to say it would be a workaround but
perhaps that is splitting hairs.

Our addressing is 192.168.0.1 thru 192.168.3.255 . Business A uses
192.168.0.1-192.168.1.255 and Business B uses 192.168.2.1 through
192.168.3.255. But there is some spill over with old machines (old
servers that there IP's are not easily changed) in each others address
space and shared machines (Plptters, Heavy Machinery) that both
companies need to be able to access So we need the 255.255.252.0 Subnet
mask to stay. We also do not have any type of spare router laying
around.

If you aren't really subnetting, then does it really matter from which
DHCP server a system gets its information?

As for a spare router, unless you have really high traffic rates, just
about any old system will do as a router. It may not even need to
have multiple interfaces.

It would seem that if you are running a network joined at layer2
between the two sister businesses, and each has different external
routers and firewall rules, you really do need some sort of
router/access control between the two. Anyone in one building could
configure themselves with an IP from the other building (DHCP perhaps
being filtered notwithstanding) and be able to go out into the big
world based not on the rules of their business, but based on the rules
of the sister business.

rick jones
--
The computing industry isn't as much a game of "Follow The Leader" as
it is one of "Ring Around the Rosy" or perhaps "Duck Duck Goose."
- Rick Jones
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...
.

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