7-26
ADSL WAN Connections
ADSL Modules for the ProCurve Secure Router
Before configuring the ATM subinterface as an unnumbered interface, you
should be aware of a potential disadvantage: if the interface to which the IP
address is actually assigned goes down, the ATM subinterface will be unavail-
able. For example, suppose you configure the ATM 1.1 subinterface as an
unnumbered interface that takes its IP address from an Ethernet interface. If
the Ethernet interface goes down, the ATM 1.1 subinterface will be unavailable
as well.
To minimize the chances of the ATM subinterface becoming unavailable, you
can assign the IP address to a loopback interface, which typically does not
go down.
To configure the ATM subinterface as an unnumbered interface, enter the
following command from the ATM subinterface configuration mode context:
Syntax: ip unnumbered <interface>
Valid interfaces from which the ATM subinterface can takes its address
include:
■ other ATM subinterfaces
■ demand interfaces
■ Ethernet interfaces or subinterfaces
■ Frame Relay subinterfaces
■ HDLC interfaces
■ loopback interfaces
■ PPP interfaces
If you configure an Ethernet interface to support virtual LANs (VLANs), you
can specify an Ethernet subinterface.
For example, you would enter the following commands to configure a loop-
back interface and then to configure the ATM 1.1 subinterface to use the IP
address assigned to that loopback interface:
ProCurve(config)# interface loopback 1
ProCurve(config-loop 1)# ip address 10.1.1.1 /24
ProCurve(config-loop 1)# interface atm 1.1
ProCurve(config-atm 1.1)# ip unnumbered loopback 1
ProCurve(config-atm 1.1)# no shut
Note You do not have to enter no shutdown to activate a loopback interface. The
status of a loopback interface automatically changes to up after you enter the
interface loopback <number> command.
To Next Page
Loading...
Need help?
General
