Avaya G430 - Page 277

Root level
command
Command Description
router ospf Enable OSPF protocol on the system and to
enter the Router configuration context
set logging
session
Manage message logging for the current
session
show
interfaces
Display interface configuration and statistics
for a particular interface or all interfaces
ICMP keepalive
The ICMP keepalive feature, formerly known as extended keepalive, is available for WAN
FastEthernet interfaces. ICMP keepalive is a mechanism for determining if a certain IP address
is reachable. The source interface sends test packets (ping) and waits for a response. If no
response is received after a certain number of tries, the connection is declared to be down.
This feature provides a quick means to determine whether the interface is up or down. This is
especially important for policy-based routing, in which it is important to determine as quickly
as possible whether the next hop is available. See
Policy-based routing on page 587.
Note:
ICMP keepalive has been replaced by the object tracking feature that supports keepalive
probes over WAN, FastEthernet, Loopback, PPPoE, and Dialer PPP interfaces. ICMP
keepalive is still supported for backward compatibility. For information about object tracking,
see
Object tracking on page 282.
Normal keepalive is sufficient for testing the status of a direct connection between two points.
However, in many situations, the system needs to know the status of an entire path in order
to ensure that packets can safely traverse it.
ICMP keepalive is a mechanism that reports on the status of an IP address and its next hop.
The destination interface is only declared to be alive if the next hop is also reachable. This
feature is critical for mechanisms such as policy-based routing that must guarantee service on
a particular path.
WAN interfaces
Administering Avaya G430 Branch Gateway October 2013 277