[rookie1010]

Hello

Are the ports on an ethernet card, physical software entities in the firmware on the NIC? would each port have a different ethernet controller?

if i am correct, does this mean that in packet forwarding, the packet data is forwarded from one software to another within the NIC card?
would such a device have four tcp/ip stacks (in case it is a 4 port ethernet)?

also from a transport layer perspective, can one forward a packet from tcp port 80 say to tcp port 81 on the same NIC card?

[mBernhardt]

To answer your questions 1 by 1:

Ports are based within TCP/IP, which is software based, rather than hardware.

The ethernet controller is the device driver which controls the physical device itself.

Packet forwarding forwards packets from one device to another. (Router to Router, Router to PC, PC to PC)

The TCP/IP stack would control all the devices (NICs) on that device. So any device only really has 1 TCP/IP "stack".

You can set up a port forward to forward packets from any port (or series of ports) to any other port (or series of ports).


And I'm sure that answer your question, but really doesn't answer your question.

TCP/IP

[rookie1010]

thanks for the reply
thanks for the replies

so one can forward packets from port 80 to port 81
my questions are with reference to figure 2 & 3 on the following link
http://www.microsoft.com/whdc/archive/ndis5.mspx

where it shows a dual NIC?