IP adresses for network cards in computer

  • Thread starter Thread starter Roger R
  • Start date Start date
R

Roger R

This must be pretty basic, but...

My computer has a main board with two Ethernet ports.
These show in the system information as two 'cards'.

The computer has one IP address, so is it right that each card should have
the same IP address?

Roger
 
This must be pretty basic, but...

My computer has a main board with two Ethernet ports.
These show in the system information as two 'cards'.

The computer has one IP address, so is it right that each card should have
the same IP address?

Roger
Click to expand...

NO. Each Ethernet port will get an unique IP address whenever a cable
is connected to a DHCP "service" or you assign one to each port.

If the computer has only one port, only one port appears to be
connected to a DHCP "service" which would get it an IP address.
 
Hi
Unless you have a specific use for the second card disable the unused card.
In many cases two cards, if active, should be configured to be on two
different Networks. Two cards on the same network id usually a "Gate" to
troubles.
Jack (MS, MVP-Networking).
 
This must be pretty basic, but...

My computer has a main board with two Ethernet ports.
These show in the system information as two 'cards'.

The computer has one IP address, so is it right that each card should have
the same IP address?

Roger
Click to expand...

NO. Each Ethernet port will get an unique IP address whenever a cable
is connected to a DHCP "service" or you assign one to each port.

If the computer has only one port, only one port appears to be
connected to a DHCP "service" which would get it an IP address.
-------------

Thanks, one possible error eliminated.

In my simple set up I have one XP port linked by cable to the router modem
and set to DHCP. This works fine no problem.

The other XP port is connected by cable to a Win98 machine.

Not sure whether it is better to set this to DHCP on both computers (doesn't
seem to work) OR to set the addresses manually. (not successful yet)

If setting the TCP/IP manually, presumably the DNS boxes are left blank?

I have Zone alarm in operation, and with DHCP the address for the XP machine
on the XP - Win98 network has entry 0.0.0.0. which can't be right.

Roger
 
Strictly speaking, IP addresses don't belong to computers but to 'interfaces'
-an interface being a wire (or radio signal) that goes somewhere.

The important points here are that two separate interfaces cannot have the
same IP address if they are to be active at the same time. Also, interfaces
which connect to two separate networks should have different subnet ranges.

With some makes of LAN card, you can 'team' two NICs into a single
interface, which will then have one IP. Both sockets will then effectively
form part of the same network. Unfortunately this is not always possible, it
depends on the driver software.
 
Back
Top