Usually, ip addresses assigned to logical interfaces such as eth0:1 are used in IPMP (IP Multi-path) configurations (equivalent to VRRP or HSRP), dot1q encapsulation on a router interface for vlan routing (router on a stick),
Can Anybody tell me
the difference between the ip on the physical interface(eth0)
and the ip configured on the logical interface(eth0:1).
Adding to Elohim's reply, the IP address on the physical interface (eth0) is always the first ip address assigned to the specific interface. When you require more IP addresses assigned to the same interface, this is usually done via the logical interfaces eth0:1, eth0:2 e.t.c.
In Windows XP, you simply go to the tcp/ip properties of the LAN interface and under the advanced section, you add multiple IP Addresses to the same lan card. In Linux, you can use the following command: