HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual page 111

Configuring Backup WAN Connections
Configuring Demand Routing for Backup Connections
A Dial-Up Interface Is Available, But the Call Fails. If a dial-up inter-
face is available and the ProCurve Secure Router attempts to establish a
connection, the call may fail for a number of reasons: a busy signal, no answer,
connection timeout, and so on. When a connection attempt fails, the router
increments the failure count for that connect sequence and then tries to use
the next connect sequence to establish a dial-up connection.
The busyout-threshold option determines the number of times the ProCurve
Secure Router processes a particular connect sequence during each connect
sequence attempt.
For example, if connect sequence 10 has a busyout-threshold of 3 and connect
sequence 11 has a busyout-threshold of 2, the router will process connect
sequence 10 three times and connect sequence 11 twice (alternating between
the two sequences). If, at the end of the five total attempts, the router cannot
establish a connection, it has made one connect sequence attempt.
If the router reaches the maximum number of connect sequence attempts, the
ProCurve Secure Router will, by default, change the status of the demand
interface to "DOWN (recovery active)." The router will remove the IP address
from the demand interface and any associated routes from the routing table.
No interesting traffic will be forwarded to the demand interface. If you have
configured an alternate route for traffic, the ProCurve Secure Router will
activate and use that route.
While the demand interface is in this recovery active state, the ProCurve
Secure Router will periodically process the connect sequences and try to
establish a dial-up connection. If the router can successfully establish a
connection, it will change the status of the demand interface to up, reinstate
the routes through the interface, and begin forwarding interesting traffic to
the demand interface.
However, if the ProCurve Secure Router cannot establish a connection, it will,
by default, continue to try the connect sequences every 120 seconds. You can
change the default settings for the recovery mode: you can configure how
often the ProCurve Secure Router attempts to establish a connection and the
number of attempts it makes in the recovery mode. From the demand interface
configuration mode context, enter:
Syntax: connect-sequence interface-recovery retry-interval <seconds> max-retries
<number>
Replace <seconds> with the number of seconds you want the demand
interface to wait between connect sequence attempts. You can specify a
number between 1 and 65535. The default setting is 120 seconds.
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