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area virtual-link
This command defines a virtual link. To remove a virtual link, use the
no
form with no
optional keywords. To restore the default value for an attribute, use the
no
form with
the required keyword.
Syntax
[no] area area-id virtual-link router-id
[authentication-key key] | [message-digest-key key-id md5 key]
[no] area area-id virtual-link router-id
authentication
[
message-digest
|
null
]
[
authentication-key
] | [
message-digest-key
md5
]
[no] area area-id virtual-link router-id
[
authentication
] [
dead-interval
seconds] [
hello-interval
seconds]
[
retransmit-interval
seconds] [
transmit-delay
seconds]
• area-id - Identifies the transit area for the virtual link.
(The area ID must be in the form of an IPv4 address.)
• router-id - Router ID of the virtual link neighbor. This specifies the Area
Border Router (ABR) at the other end of the virtual link. To create a virtual
link, enter this command for an ABR at both ends of the link. One of the
ABRs must be next to the isolated area and the transit area at one end of
the link, while the other ABR must be next to the transit area and backbone
at the other end of the link.
• authentication-key key - Sets a plain text password (up to 8 characters)
that is used by neighboring routers on a virtual link to generate or verify the
authentication field in protocol message headers. A separate password can
be assigned to each network interface. However, this key must be the same
for all neighboring routers on the same network (i.e., autonomous system).
This key is only used when authentication is enabled for the backbone.
• message-digest-key key-id md5 key - Sets the key identifier and
password to be used to authenticate protocol messages passed between
neighboring routers and this router when using message digest (MD5)
authentication. The key-id is an integer from 1-255, and the key is an
alphanumeric string up to 16 characters long. If MD5 authentication is used
on a virtual link, then it must be enabled on all routers within an autonomous
system; and the key identifier and key must also be the same for all routers.
• authentication - Specifies the authentication mode. If no optional
parameters follow this keyword, then plain text authentication is used along
with the password specified by the
authentication-key
. If
message-digest
authentication is specified, then the
message-digest-key
and
md5
parameters must also be specified. If the null option is specified, then no
authentication is performed on any OSPF routing protocol messages.
- message-digest - Specifies message-digest (MD5) authentication.
- null - Indicates that no authentication is used.
• dead-interval seconds - Specifies the time that neighbor routers will wait
for a hello packet before they declare the router down. This value must be
42-30
IP Routing Commands
42