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Explain how to set an alias for the NIC.

45.Explain how to set an alias for the NIC.
Ans.
1. It is possible to assign more than one IP address to a single NIC, these addresses are called as aliases.

2. This is achieved by using the ifconfig and route commands, to add another IP address, 192.168.166.56, to eth0, we have to execute these commands:
#ifconfig eth0:1 192.168.166.56
#route addr – host 192.168.166.56

3. The first command binds the IP address to virtual interface eth0:1 and the second command adds a route for the address to the actual device eth0.

4. Another method is adding second IP address to a single NIC by creating an alias file.

5. The configuration file for device eth0 is /etc/sysconfig /nwtwork-scripts/ifcfg-eth0

6. The above file is copied to another file called ifcfgeth0:1 in the same directory.

7. We need to open the newly copied file and change the line that reads:
DEVICE= eth0 to DEVICE=eth0:1

8. The service of network is restarted for above changes to be affected, these effects are permanent.

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