2 network cards on same subnet. Is this ok?

ForumKid · 01-12-2002, 12:23 PM

eth0=192.168.3.2
eth1=192.168.3.3

Does this pose a problem?

I tried changing eth1 to 10.0.0.2 and then i couldnt access the box.

ForumKid · 01-12-2002, 12:27 PM

Well it is posing some type of problem.

It takes about 15mins after the server is restarted before ssh is allowed on 192.168.3.2. ssh is allowed right away on 192.168.3.3.
pop3 also doesnt work. Its like after 5 mins everything kicks in. So i disabled the nic and restarted server. Everything is beautiful.
So what can i change it to to be correct. Id really like it to be a 10.0.0.0 network. I think Raz said it should be, but then if I change it, no access.
Has anyone ever had this issue?
Thanks

ForumKid · 01-12-2002, 02:42 PM

Can someone give me an example of two nic ip addresses that are on the same box?

DMR · 01-12-2002, 05:41 PM

It doesn't matter if you use the 10.x.x.x or 192.168.x.x range of IP addresses, both are private, non-routeable ranges.

The problem is that 2 NIC in the same machine really don't like to live on the same subnet. You can find out more about the issues by doing a Google search on the phrase "two NICs on the same subnet". I think the problem has also been addressed here; use the search function to check the archives.

Could you post the output of ifconfig just for grins?

bluecadet · 01-12-2002, 06:54 PM

yeah, it's not good practise to do what you're doing, and so it's not allowed under un*x, or at least linux. it's inconsistent with standard ethernet architecture. you can either run them on diffferennt sub nets and perhaps find out about kernel bridging, or... erm.. get a hub. OR install a token ring netwrok.. ouch.

windows lets you get away with ti... but it shouldn't, and in this kind situation, it's really a case of having to bute the bullet and accept that it's a bad thing to do, even though your situation would benefit from it.

ForumKid · 01-14-2002, 09:10 AM

Hi,
This is what I have now
eth0=192.168.3.2
eth1=192.168.1.2

and things work now.
THanks for your explanation.

I guess they also have to be on the same mask. I tried changing the card to 10.0.0.x(255.0.0.0) and things didnt work. But it could also be that the switch im using is for 10.0.0.x and 192.168.x.x. traffic.

Thanks again.