Re: 2 ip numbers on 1 computer

In article <eXpZVHGTHHA.1636@xxxxxxxxxxxxxxxxxxxx>, Lem
<lemp40@xxxxxxxxxxx> wrote:
Steve,

I understand _how_ to add multiple static IPs to a single NIC, but _why_
would one do this, and how does it work?

Hi, Lem. I can't think of a setup in a typical home network where
you'd want multiple static IPs on a singe NIC. A computer acting as a
web server might do that in order to host multiple sites.

If a NIC has multiple IP addresses assigned, what gets placed in the
"source IP address" portion of the IP header of packets sent by that
NIC? The top-most IP address in the list? I wouldn't think that it
would duplicate each outgoing packet for each separate IP address.

If a packet goes to one of the NICs subnets, I assume that the source
IP address is the one in the same subnet as the destination IP
address. I don't know what would happen otherwise.

I assume that if I configure my NIC with:

192.168.0.101 and
192.168.1.101

I can _receive_ packets from other computers on either the 192.168.0.x
subnet or the 192.168.1.x subnet (without the need for a router).

What happens if my 2-IP address NIC transmits packets? Who can receive
them (without going through a router)?

That's should work the same as for a 1-IP NIC. A device in the same
subnet as one of the NICs addresses can receive packets directly.
Anything else requires a gateway address and a router.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com
.

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