Re: Restricting ports/services to specific interfaces

["Simon Coulter" <shc@xxxxxxxxxxxxxxxxx>]

M
mkrouse@co.ottawa.mi.us wrote:
>If just the T/R interface is active - the DHCP traffic goes in/out through
>it using it's IP address (in LLC format) and the PC's get their IP
>addresses and everything works fine.

Yes.  Only one interface is active so how else would you expect it to work?

>If Ethernet and T/R interfaces are both active - DHCP requests are
>received on both interfaces, but the responses only go out the Ethernet
>interface (in ETHV2 and 802.3 format) and the PC's don't get IP addresses.

That's because they are on the same subnet and you can't choose which
interface will be used.  TCP thinks it can reach your PCs by either
interface so it picks one.  I suspect your ethernet interface is either
started first or has a lower IP address.  Both those factors can affect
which interface is used but neither is reliable.

>I would like to force DHCP to use the T/R interface (or that IP address)
>as it seems that would solve the problem.

Subnetting is how you do that!

Regards,
Simon Coulter.

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