Re: Win95 won't forget old IP address

[Ted Lemon <[e-mail]>]

> Conclusion?  The Win95 DHCP client is broken.

Naw.   The router is broken.

> In any case, we are somewhat confused about why we would need to do this.
> Using a broadcast address at both the link layer and the IP layer at this
> step seems very expensive and unnecessary...  Why can't we just use the
> client's MAC address at the link layer, regardless of what's at the IP layer?

Ideally, the router will use the IP broadcast address but unicast the
packet to the Win95 client.   The reason why the IP broadcast address
is required is that the client doesn't know what network it's on, so
unless it is bypassing its IP stack, there's no guarantee that a
packet addressed either to its new address or to the subnet broadcast
for the net its on will actually be received - normally an IP stack is
expected to silently discard incoming packets not addressed to it.

> If this is true, it may be impossible for us to support Windows 95 DHCP
> clients, until Microsoft fixes this.  This would be something of a disaster;
> people have been clamoring for support for Windows 95 DHCP clients, but it
> appears that without modifying either the Cisco code or the Microsoft code,
> it may be impossible.

There is a third option - turn off BOOTP forwarding in your Cisco
router and run a BOOTP gateway on some machine on each local network.
Granted, if you don't have servers on every net, this could be very
expensive, but if you do have servers on every net, it could work out
pretty well.

You could also contact Cisco and see if you can get a software update
that fixes the problem.   I don't know from Cisco version numbers, so
I can't help you there.

			       _MelloN_