Icmp Keepalive - Avaya G250 Administration

Table 8: Modem dial backup logging messages (continued)
Log Message
IPCP Up/Down
IPCP IP reject

ICMP keepalive

The ICMP keepalive feature, formerly known as extended keepalive, is available for WAN Fast
Ethernet 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
Note:
ICMP keepalive has been replaced by the object tracking feature, which supports
Note:
keepalive probes over WAN, FastEthernet, loopback, PPPoE, and Dialer PPP
interfaces and Frame relay sub-interfaces. ICMP keepalive is still supported for
backward compatibility. For information about object tracking, see
tracking
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.
Severity Possible cause
Debug PPP uses IPCP to define the IP
characteristics of the session. IP
packets cannot be exchanged
until IPCP is in the Up state.
Warning This message is generated
when IPCP attempts to define
the IP characteristics for a PPP
session, but does not have the
IP address of the local interface
to define the session. Without IP
address information on both
sides of the session, the PPP
session cannot begin passing IP
traffic.
on page 171.
Configuring policy-based routing
ICMP keepalive
Action
None required.
Troubleshooting steps:
Check Dialer
●
interface
configuration to
ensure an IP
address is
configured,
either as a static
address or
through
Dynamic IP
addressing or
through IP
unnumbered.
6 of 6
on page 465.
Object
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