Altering Ospf Intervals - HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual

IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring OSPF
N o t e
Interval Meaning
hello the time between
sending hellos
dead the time to wait
for a hello before
determining a link
is down
13-58

Altering OSPF Intervals

OSPF can be a relatively chatty protocol. For example, an interface sends its
neighbor a hello message every 10 seconds to notify it that the link is still up.
If necessary, you can change the timing intervals for such messages. You
configure these intervals for individual interfaces.
To change the hello interval for a logical interface, move to the configuration
mode context for that interface and enter:
Syntax: ip ospf hello-interval <value>
The value can be between 1 and 65,535 seconds.
When you change an interface's hello interval, you must remember to change
its peer interface's dead interval accordingly. Otherwise, the peer may wrongly
decide the interface is down. You can determine how many times longer the
dead interval should be than the hello interval according to how reliable your
network is. For example, the default dead interval is four times longer than
the hello interval, which allows for three hello packets to go astray without
changing the status of the link.
If a peer interface is having problems with flapping, you can change the
retransmit interval. This is the minimum amount of time the router must wait
between sending LSAs. Even if several topological changes occur during this
interval, the interface will wait until the retransmit timer expires to send the
LSA.
Move to the logical interface configuration mode context and use the com-
mands shown in Table 13-8 to alter OSPF timers for a particular interface.
Table 13-8. OSPF Intervals for Interfaces
Default Setting Range
10 seconds
40 seconds
Command Syntax
1 to 65,535 seconds ip ospf hello-interval <seconds>
1 to 65,535 seconds ip ospf dead-interval <seconds>