Multiple IP interface creation with down status
 

Hi,
I have to implement hardware redundancy.I have 2 linux machine for this and each have similar configuration/hardware. Lets say two machine Linux1 and Linux2. Currently Linux1 have one NIC and it has 4 IP address bind on it. Now I have to down the Linux1 and up Linux2 with same Ip addresses.
Could it possible to configure all the Ip (same)address on both Linux1 and Linux2 and Linux1 have eth:x status UP while Linux2 have eth:y status down.
I am trying it but on Linux2 machine I cant able to create multiple Ip interfaces with down status. Could you please suggest me regarding this.
Thanks a lot.

Sounds like a homework assignment.

What version/distro of Linux are you using? What kind of hardware? What are you using for failover between the boxes? What services are running that you need to have continue?

There are things that make no sense in this configuration:

1. One NIC, with 4 IP addresses? What's the point? You have a single point of failure, so if that one NIC fails, any addresses go with it.
2. Same configured on another box? Again, what's the point? Same single point of failure.

If you're going to make it redundant, what are you using to fail over between the two? Whatever you're using could easily be modified to create the interfaces, give them addresses, and even change the MAC address info, so you won't get ARP table problems. On some distros, there are interface configuration files that you can edit, so they can be present, but have whatever properties you want. Since you don't say the distro, hard to tell you where to look, but they'll be under /etc.

If you are using OS RHEL or CentOS then you need to implement RHEL cluster suite. In this cluster suit you need to assign VIPs(Virtual IPs) for solving this situation for more info about RHEL cluster suit have a look in this link.

http://www.redhat.com/docs/en-US/Red...iew/index.html

Hope this will solve your problem.

Regards
Charanjit Singh

its prototyping to simulate some real time operation of tele communication.
The need of such configuration is to make the redundant unit.so that in case of up gradation of BOX1, box2 can take charge either manually or automatically(by health monitoring) and vice varsa.
y i used multiple IP on same physical port is due to differentiate the nature of data.
I am using red-hat for simulation but finally I have to implement it on some MIPS processor.