Add second network interface

[wpaynter]

I installed Centos 5.5 and during the install I only setup my first static IP address for eth0. I left eth1 unconfigured. I have another IP on the same network that I want to use on this system as well.

Is there any benefit having the second IP address on an entirely different network interface? or should I just add the IP address to the system in the DirectAdmin panel and let it have both ip's on the same physical interface?

If I want to have the second IP set to the second physical interface do I need to add configuration to /etc/sysconfig/ somewhere?

Thanks !

 

[floyd]

I do not see any advantage unless you are going to be transferring more data than the 1 nic can handle.

 

[nobaloney]

If I want to have the second IP set to the second physical interface do I need to add configuration to /etc/sysconfig/ somewhere?

That's OS dependent. However note that DirectAdmin will set up IP#s to use your main NIC by default. There have been discussions on these forums on how to use both NICs, but it's not what DirectAdmin does by default.

We use our second NIC in our servers to create a private network between the servers, for backups, and for high speed transit between machines of data that doesn't need to be on the public Internet.

Jeff

 

[tomtom901]

Jeff's right. You could use a second NIC for internal use (things such as a backup), and because the data will never leave your internal network, it won't cost you bandwith.

An other option is to 'lacp' on the switch if you want to speed things up. And for redundancy ofcourse.

 

[nobaloney]

We built out our first datacenter for data transit redundancy; two drops, two routers, two switches, two NICs in every machine.

It uses some extra IP#s per private network and affords automatic switchover.

After three years in that DC, when we moved, we eliminated it, because we never had a problem in that area. Sure, some problems, but never for that. So for us it didn't make sense.

Jeff

 

[judab2]

Hi,

First you cant have two interfaces in the same network segment
For example you cant have

eth0 ip address 192.168.1.10/24
and also
eth1 ip address 192.168.1.11/24

because each network interface must e on different network segment

how ever if you still want to use two network interfaces on the same segment you must use do bonding .. look for google for 'bond0' or 'linux bond interface' .

otherwise if you do not use bond then each interface must be on different ip network

for example
eth0 ip address 192.168.1.10
and eth1 ip address 192.168.2.10

remeber to have only one default gateway on the linux

best wishes