Changing the transit-delay on a virtual link
Syntax:
area
area-id
virtual link
ip-address
transit-delay [0-3600]
Used in the router OSPF context on both ABRs in a virtual link to change the estimated number of seconds it
takes to transmit a link state update packet over a virtual link. The
transit-delay
setting must be the same on
both ABRs on a given virtual link.
area-id
Specifies the OSPF area in which both ABRs in a given virtual link operate. In this use, the area ID is
sometimes termed "transit area ID." This value must be the same for both ABRs in the virtual link.
ip-address
For an ABR in a given virtual link, this is the IP address used to create the link on that ABR. (This IP address
matches the IP address of the interface on the opposite end of the virtual link. See the description of
ip-
address
in the syntax description under
on page 216.)
Use
show ip ospf virtual-link
ip-address
to view the current setting.
Default: 1 second; range: 1–3600 seconds
Example
To change the hello-interval on the virtual link configured for the network in
Figure 37: Defining OSPF virtual
on page 217 to 60 seconds:
• On routing switch "A" (IP address 10.0.0.1) you would use the following command to reconfigure the current
hello-interval to 60 seconds:
switch(ospf)# area 1 virtual-link 209.157.22.1 hello-interval 60
• On routing switch "C" (IP address 209.157.22.1) you would use the following command to reconfigure the
current hello-interval to 60 seconds
switch(ospf)# area 1 virtual-link 10.0.0.1 hello-interval 60
Configuring OSPF authentication on a virtual link
For more information, see
Configuring OSPF authentication on a virtual link
on page 261.
Authenticating OSPF MD5 on a virtual link
Syntax:
ip ospf md5-auth-key-chain
chain-name-string
no ip ospf [
ip-address
] authentication
Used to configure MD5 authentication in the router OSPF context on both ABRs in a virtual link. The MD5
authentication takes effect immediately, and all OSPF packets transmitted on the link contain the designated key.
Every OSPF packet received on the interface for the virtual link on each ABR is checked for the key. If it is not
present, the packet is dropped.
To disable MD5 authentication on an ABR interface used for a virtual link, use the
no
form of the command. The
password must be the same on both ABRs on a given virtual link.
Chapter 11 Open Shortest Path First Protocol (OSPF)
219
