Configuring IP Addressing

Loopback Interfaces

For example, if you configure a VLAN with IP address 172.16.100.8/24, you cannot configure a loopback interface with IP address 172.16.100.8. In the same way, if you configure a loopback interface (lo1) with IP address 172.16.101.8, you cannot configure another loopback interface (lo2) with IP address 172.16.101.8.

You can configure multiple IP addresses on a loopback interface (lo0 to lo7). Up to thirty-two IP addresses are supported on a loopback interface. The following example shows valid IP address configurations on two loopback interfaces.

ProCurve(config)# interface loopback 0

ProCurve (lo0)# ip address 172.16.101.8

ProCurve (lo0)# ip address 172.16.101.9

ProCurve (lo0)# exit

ProCurve (config)# interface loopback 1

ProCurve (lo1)# ip address 172.16.102.1

ProCurve (lo1)# ip address 172.16.102.2

Displaying Loopback Interface Configurations

To display the list of loopback interfaces which have been assigned IP addresses, enter the show ip command.

In the show ip command output, information about configured loopback interfaces is displayed below other IP configuration parameters, such as packet time-to-live (TTL) and ARP age-out values, and VLAN IP configura­ tions. The following example displays the IP addresses configured for two user-defined loopback interfaces (lo1 and lo2).

8-18