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DHCP traffic Blocking

Hi All,

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.

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.

Thanks

Dan

Reply to
danbricker
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This is not something that can be handled in a Layer 2 switch such as your

4000.

IP addresses are seldom hardwired.

Then you need to either clean up your addressing scheme or obtain the necessary routers. Note that a quite adequate router for many purposes can be made from a used PC purchased for 25 bucks off of ebay or your local liquidator, two NICs, and a copy of Linux.

The general rule is _one_ DHCP server per routing domain. If you don't have any other option then hardware the MAC addresses into your DHCP tables or just configure everything for static IPs.

Reply to
J. Clarke

But he could use a VLAN, which is supported by the 4000.

Reply to
none

but he wants logical links between the 2 - so now he has to route between the VLANs - same problem, different cabling.

personally i would use the Procurve elsewhere and put a layer 3 switch in its place (with VLANs in case). That way he is ready for the next L3 / filtering problem.

Reply to
stephen

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