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, u se t he
no
form with
the required keyword.
Syntax
[no] area area-id virtual-link ro uter-id
[authentication -key key] | [message-digest-key key-id md5 key]
[no] area area-id virtual-link rou ter-id
authentication
[
message-digest
|
null
]
[
authentication-key
] | [
message-digest-key
md5
]
[no] area area-id virtual-link rou ter-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 IPv 4 address .)
• router-id - Router ID of the virtual link neighbor. This spec ifies the A rea
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 th e
ABRs must be next to the isolated area and the tran sit area at one end of
the link, while the other ABR must be next to the transit area and back bon e
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 verif y th e
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., autono mou s syste m ).
This key is only used when authentication is enabled for the b ackbone .
• 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 in tege r fro m 1 -255, and th e 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 optiona l
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 sp ecified , then n o
authentication is performed on any OSPF routing protocol messages.
- me ssage-digest - Specifies message- digest (MD5) au thenti catio n.
- null - Indicates that no authentication is used.
• dead-interval seconds - Specifies the time that neighb or routers will w ait
for a hello packet before they declare the router down. This value must be
42-30
IP Routing Commands
42