Avaya G250 Administration page 159

!Step 11
G250-001(super)# interface console
G250-001(super-if:Console)# async mode interactive
Done!
G250-001(super-if:Console)# async modem-type MultiTech-ZBA
Done!
G250-001(super-if:Console)# exit
G250-001(super)#
Step 12
G250-001(super)# interface serial 2/1:1
G250-001(if:serial 2/1:1)# backup interface Dialer 1
Done!
G250-001(if:serial 2/1:1)# exit
G250-001(super)#
Step 13
G250-001(super)# router ospf
G250-001(super router:ospf)# network 149.49.4.4 0.0.0.3 area 0.0.0.5
Done
G250-001(super router:ospf)# exit
G250-001(super)#
An explanation of the steps taken is as follows:
1. Assign an IP address to the Loopback interface for use with modem dial backup using the
interface loopback command. This step allows the Dialer interface to be configured as
an IP unnumbered link and still participate in OSPF routing.
2. Create an access control list using the ip access-control-list command. The
access control list determines which traffic is permitted to use the interface. In this example,
access control list 305 is configured to block all traffic other than VoIP signalling traffic. The
primary purpose of the access control list is to block bearer traffic from trying to use the
Dialer interface. The Dialer interface generally has insufficient bandwidth to support bearer
traffic. For more information on configuring access control lists, see
policy on page 441.
3. Create the Dialer interface using the interface dialer command. The Dialer interface
is created and is available as a backup link for a WAN interface. Only one Dialer interface
can be created on the G250/G350.
4. Assign a PPP authentication method using the ppp chap hostname command. The
Dialer interface authenticates its PPP sessions to the remote RAS server using CHAP
authentication and a user name of area5. The user name area5 must be configured on the
RAS as a legitimate user.
5. Assign an initial delay for dialing using the dialer persistent initial delay
command. The initial delay prevents the dialer from dialing out unnecessarily on reboot.
The primary WAN interface often requires a few moments to register itself as up, and during
that period, the initial delay prevents the device from activating the dialer.
Modem dial backup
Chapter 19: Configuring
Issue 1.1 June 2005 159