1162 Configuring OSPF and OSPFv3
Configuring Virtual Links

Beginning in Privileged EXEC mode, use the following commands to

configure OSPF Virtual Links.

Command Purpose
configure Enter global configuration mode.
router ospf Enter OSPF configuration mode.
area

area-id

virtual-link
neighbor-id
Create the OSPF virtual interface for the specified area-
id and neighbor router. The

neighbor-id

variable is the IP
address of the neighboring router.
area
area-id
virtual-link

router-id

[authentication
[message-digest | null]]
[[authentication-key
key
]
| [message-digest-key

key-

id

md5
key
]]
Create the OSPF virtual interface for the specified area-
id and neighbor router.
Use the optional parameters to configure authentication
for the virtual link. If the area has not been previously
created, it is created by this command. If the area already
exists, the virtual-link information is added or modified.
authentication
—Specifies authentication type.
message-digest
—Specifies that message-digest
authentication is used.
null
—No authentication is used. Overrides password or
message-digest authentication if configured for the
area.
md5
—Use MD5 Encryption for an OSPF Virtual Link
key
—Authentication key for the specified interface.
(Range: 8 bytes or less if the authentication type is
simple and 16 bytes or less if the type is encrypt.)
key-id
—Authentication key identifier for the
authentication type encrypt. (Range: 0-255)
area
area-id
virtual-link
neighbor-id
retransmit-
interval
seconds
Set the OSPF retransmit interval for the virtual link
interface.
The
seconds
variable is the number of seconds to wait
between retransmitting LSAs if no acknowledgement is
received. (Range: 0–3600)