Multiple NICs w/same Static IP

[cgasmith]

Yea, I know, us crazy hardware testers. So after reading some of the forums and wiki's here I thought wow, the people around here know their stuff . I thought I'd post a question. Under linux (irregardless of which distro) I have a topology of a single nic w/static ip as a tftp server that is replicated 4 times so that means I have 4 nics all with the same static IP and the devices downstream are hardcoded with static ip's as well. I have almost completed scripting to enable/disable which 1/4 I want to talk to using ifconfig and up/down commands, but it occurs to me that it may be easier than I thought, is it possible to provide some form of reference like eth0://192.168.1.1 as opposed to using the routing tables?
Any Ideas??
-C

[Compunuts]

This one seems to be for Debian and there is another solution for Red Hat. But it should be cross-platform as long as you have it multiple config sections.

NIC bonding is not that hard as it was a while ago.

HTH ....

[cgasmith]

NIC Bonding, aka the first step towards load-sharing or redundancy, is fairly easy this day and age, and most reptuable drivers have settings for doing that for each of their own cards. But what I was aluding to, crazy test dude I am, is I have several dozen ip devices that I need to communicate to all from one computer and, the catcher, all have fixed and identical ip addresses what I was thinking of doing is some form of NAT where the adaptor that the device I wanted to talk to was part of the NAT table or use some from of too-smart and $$$ high end router to do that.
Thanks to any NAT / High-End router guru that can answer this challenge. In the mean time, I'm using several dozen computers.....

[redhead]

what I was thinking of doing is some form of NAT where the adaptor that the device I wanted to talk to was part of the NAT table or use some from of too-smart and $$$ high end router to do that.

Let me see if I undestand this, your adaptor here, is this a protocol like SMTP/HTTP/P2P/etc ?

If it is, then it's not that difficult to make a smart routing table with NAT/PREROUTING.

If you're talking about the given interface, ie:

• get a request on eth2
  • answer that request through eth2
• get a request on eth4
  • answer that request through eth4
• etc

Then it's even simpler.

If it is somethign with IP segments, ie:

• get a request for 192.168.1.123/28
  • forward that through eth3
• get a request for 192.168.1.131/28
  • forward that through eth2
• etc

Then it's a simple NAT/POSTROUTING aswell.

The $$$ high end router can be your *nix box.

[zonofabee]

Another thing that you could possibly consider is to use the MAC address of each machine, and identify them that way. Since the IP address is the same, this doesn't apply to the MAC address of each machine. Each MAC address is unique. And the best way to find the MAC address of each machine is to use "arp". I believe that the router has a built-in application in the security section, to isolate communication to another machine by identifying it's MAC address.

Cheers!