OSPF Commands

This chapter explains the function and syntax of the Open Shortest Path First (OSPF) routing commands. For more information about defaults and usage guidelines, see the corresponding chapter of the Cisco IOS IP and IP Routing Command Reference, Release 12.1.

area authentication

To enable authentication for an OSPF area, use the area authentication router configuration command. To remove an area's authentication specification or a specified area from the configuration, use the no form of this command.

area area-id authentication [message-digest]

no area area-id authentication

no area area-id

Syntax Description

area-id

Identifier of the area for which authentication is to be enabled. The identifier can be specified as either a decimal value or an IP address.

message-digest

(Optional) Enables MD5 authentication on the area specified by area-id.

area-id	Identifier of the area for which authentication is to be enabled. The identifier can be specified as either a decimal value or an IP address.
message-digest	(Optional) Enables MD5 authentication on the area specified by area-id.

area default-cost

To specify a cost for the default summary route sent into a stub or NSSA area, use the area default-cost router configuration command. To remove the assigned default route cost, use the no form of this command.

area area-id default-cost cost

no area area-id default-cost cost

no area area-id

Syntax Description

area-id

Identifier for the stub or NSSA area. The identifier can be specified as either a decimal value or as an IP address.

cost

Cost for the default summary route used for a stub or NSSA area. The acceptable value is a 24-bit number.

area-id	Identifier for the stub or NSSA area. The identifier can be specified as either a decimal value or as an IP address.
cost	Cost for the default summary route used for a stub or NSSA area. The acceptable value is a 24-bit number.

area nssa

To configure an area as a not so stubby area (NSSA), use the area nssa router configuration command. To remove the NSSA distinction from the area, use the no form of this command.

area area-id nssa [no-redistribution] [default-information-originate]

no area area-id nssa

no area area-id

Syntax Description

area-id

Identifier of the area for which authentication is to be enabled. The identifier can be specified as either a decimal value or an IP address.

no-redistribution

(Optional) Used when the router is a NSSA ABR and you want the redistribute command to import routes only into the normal areas, but not into the NSSA area.

default-information-
originate

(Optional) Used to generate a Type 7 default into the NSSA area. This argument only takes effect on NSSA ABR or NSSA ASBR.

area-id	Identifier of the area for which authentication is to be enabled. The identifier can be specified as either a decimal value or an IP address.
no-redistribution	(Optional) Used when the router is a NSSA ABR and you want the redistribute command to import routes only into the normal areas, but not into the NSSA area.
default-information- originate	(Optional) Used to generate a Type 7 default into the NSSA area. This argument only takes effect on NSSA ABR or NSSA ASBR.

area range

To consolidate and summarize routes at an area boundary, use the area range router configuration command. To disable this function, use the no form of this command.

area area-id range address mask [advertise | not-advertise]

no area area-id range address mask [advertise | not-advertise]

no area area-id

Syntax Description

area-id

Identifier of the area about which routes are to be summarized. It can be specified as either a decimal value or as an IP address.

address

IP address.

mask

IP mask.

advertise

(Default) Sets the address range status to advertise and generates a Type 3 summary LSA.

not-advertise

Sets the address range status to DoNotAdvertise. The Type 3 summary LSA is suppressed and the component networks remain hidden from other networks.

area-id	Identifier of the area about which routes are to be summarized. It can be specified as either a decimal value or as an IP address.
address	IP address.
mask	IP mask.
advertise	(Default) Sets the address range status to advertise and generates a Type 3 summary LSA.
not-advertise	Sets the address range status to DoNotAdvertise. The Type 3 summary LSA is suppressed and the component networks remain hidden from other networks.

area stub

To define an area as a stub area, use the area stub router configuration command. To disable this function, use the no form of this command.

area area-id stub [no-summary]

no area area-id stub

no area area-id

Syntax Description

area-id

Identifier for the stub area; either a decimal value or an IP address.

no-summary

(Optional) Prevents an ABR from sending summary link advertisements into the stub area.

area-id	Identifier for the stub area; either a decimal value or an IP address.
no-summary	(Optional) Prevents an ABR from sending summary link advertisements into the stub area.

area virtual-link

To define an OSPF virtual link, use the area virtual-link authentication router configuration command with the optional parameters. To remove a virtual link, use the no form of this command.

area area-id virtual-link router-id [authentication [message-digest | null]] [hello-interval seconds] [retransmit-interval seconds] [transmit-delay seconds] [dead-interval seconds] [[authentication-key key] | [message-digest-key keyid md5 key]]

no area area-id virtual-link router-id [authentication [message-digest | null]] [hello-interval seconds] [retransmit-interval seconds] [transmit-delay seconds] [dead-interval seconds] [[authentication-key key] | [message-digest-key keyid md5 key]]

no area area-id

Syntax Description

area-id

Area ID assigned to the transit area for the virtual link. This can be either a decimal value or a valid IP address. There is no default.

router-id

Router ID associated with the virtual link neighbor. The router ID appears in the show ip ospf display. It is internally derived by each router from the router's interface IP addresses. This value must be entered in the format of an IP address. There is no default.

authentication

(Optional) Specifies authentication type.

message-digest

(Optional) Specifies that message-digest authentication is used.

null

(Optional) No authentication is used. Overrides password or message-digest authentication if configured for the area.

hello-interval seconds

(Optional) Time in seconds between the hello packets that the Cisco IOS software sends on an interface. Unsigned integer value to be advertised in the software's hello packets. The value must be the same for all routers and access servers attached to a common network. The default is 10 seconds.

retransmit-interval seconds

(Optional) Time in seconds between link state advertisement retransmissions for adjacencies belonging to the interface. Expected round-trip delay between any two routers on the attached network. The value must be greater than the expected round-trip delay. The default is 5 seconds.

transmit-delay seconds

(Optional) Estimated time in seconds it takes to transmit a link state update packet on the interface. Integer value that must be greater than zero. Link state advertisements in the update packet have their age incremented by this amount before transmission. The default value is 1 second.

dead-interval seconds

(Optional) Time in seconds that a software's hello packets are not seen before its neighbors declare the router down. Unsigned integer value. The default is four times the hello interval, or 40 seconds. As with the hello interval, this value must be the same for all routers and access servers attached to a common network.

authentication-key key

(Optional) Password to be used by neighboring routers. Any continuous string of characters that you can enter from the keyboard up to 8 bytes long. This string acts as a key that will allow the authentication procedure to generate or verify the authentication field in the OSPF header. This key is inserted directly into the OSPF header when originating routing protocol packets. A separate password can be assigned to each network on a per-interface basis. All neighboring routers on the same network must have the same password to be able to route OSPF traffic. The password is encrypted in the configuration file if the service password-encryption command is enabled. There is no default value.

message-digest-key keyid md5 key

(Optional) Key identifier and password to be used by neighboring routers and this router for MD5 authentication. The keyid argument is a number in the range 1 to 255. The key is an alphanumeric string of up to 16 characters. All neighboring routers on the same network must have the same key identifier and key to be able to route OSPF traffic. There is no default value.

area-id	Area ID assigned to the transit area for the virtual link. This can be either a decimal value or a valid IP address. There is no default.
router-id	Router ID associated with the virtual link neighbor. The router ID appears in the show ip ospf display. It is internally derived by each router from the router's interface IP addresses. This value must be entered in the format of an IP address. There is no default.
authentication	(Optional) Specifies authentication type.
message-digest	(Optional) Specifies that message-digest authentication is used.
null	(Optional) No authentication is used. Overrides password or message-digest authentication if configured for the area.
hello-interval seconds	(Optional) Time in seconds between the hello packets that the Cisco IOS software sends on an interface. Unsigned integer value to be advertised in the software's hello packets. The value must be the same for all routers and access servers attached to a common network. The default is 10 seconds.
retransmit-interval seconds	(Optional) Time in seconds between link state advertisement retransmissions for adjacencies belonging to the interface. Expected round-trip delay between any two routers on the attached network. The value must be greater than the expected round-trip delay. The default is 5 seconds.
transmit-delay seconds	(Optional) Estimated time in seconds it takes to transmit a link state update packet on the interface. Integer value that must be greater than zero. Link state advertisements in the update packet have their age incremented by this amount before transmission. The default value is 1 second.
dead-interval seconds	(Optional) Time in seconds that a software's hello packets are not seen before its neighbors declare the router down. Unsigned integer value. The default is four times the hello interval, or 40 seconds. As with the hello interval, this value must be the same for all routers and access servers attached to a common network.
authentication-key key	(Optional) Password to be used by neighboring routers. Any continuous string of characters that you can enter from the keyboard up to 8 bytes long. This string acts as a key that will allow the authentication procedure to generate or verify the authentication field in the OSPF header. This key is inserted directly into the OSPF header when originating routing protocol packets. A separate password can be assigned to each network on a per-interface basis. All neighboring routers on the same network must have the same password to be able to route OSPF traffic. The password is encrypted in the configuration file if the service password-encryption command is enabled. There is no default value.
message-digest-key keyid md5 key	(Optional) Key identifier and password to be used by neighboring routers and this router for MD5 authentication. The keyid argument is a number in the range 1 to 255. The key is an alphanumeric string of up to 16 characters. All neighboring routers on the same network must have the same key identifier and key to be able to route OSPF traffic. There is no default value.

auto-cost

To control how OSPF calculates default metrics for the interface, use the auto-cost router configuration command. To assign cost based only on the interface type, use the no form of this command.

auto-cost reference-bandwidth ref-bw

no auto-cost reference-bandwidth

Syntax Description

reference-bandwidth ref-bw

Rate in megabits per second (bandwidth). The range is 1 to 4294967; the default is 100.

reference-bandwidth ref-bw	Rate in megabits per second (bandwidth). The range is 1 to 4294967; the default is 100.

default-information originate (OSPF)

To generate a default external route into an OSPF routing domain, use the default-information originate router configuration command. To disable this feature, use the no form of this command.

default-information originate [always] [metric metric-value] [metric-type type-value] [route-map map-name]

no default-information originate [always] [metric metric-value] [metric-type type-value] [route-map map-name]

Syntax Description

always

(Optional) Always advertises the default route regardless of whether the software has a default route.

metric metric-value

(Optional) Metric used for generating the default route. If you omit a value and do not specify a value using the default-metric router configuration command, the default metric value is 10. The value used is specific to the protocol.

metric-type type-value

(Optional) External link type associated with the default route advertised into the OSPF routing domain. It can be one of the following values:

1---Type 1 external route

2---Type 2 external route

The default is Type 2 external route.

route-map map-name

(Optional) Routing process will generate the default route if the route map is satisfied.

always	(Optional) Always advertises the default route regardless of whether the software has a default route.
metric metric-value	(Optional) Metric used for generating the default route. If you omit a value and do not specify a value using the default-metric router configuration command, the default metric value is 10. The value used is specific to the protocol.
metric-type type-value	(Optional) External link type associated with the default route advertised into the OSPF routing domain. It can be one of the following values: 1---Type 1 external route 2---Type 2 external route The default is Type 2 external route.
route-map map-name	(Optional) Routing process will generate the default route if the route map is satisfied.

default-metric (OSPF)

To set default metric values for the OSPF routing protocol, use this form of the default-metric router configuration command. To r eturn to the default state, use the no form of this command.

default-metric number

no default-metric number

Syntax Description

number

Default metric value appropriate for the specified routing protocol.

number	Default metric value appropriate for the specified routing protocol.

distance ospf

To define OSPF route administrative distances based on route type, use the distance ospf router configuration command. To restore the default value, use the no form of this command.

distance ospf {[intra-area dist1] [inter-area dist2] [external dist3]}

no distance ospf

Syntax Description

intra-area dist1

(Optional) Sets the distance for all routes within an area. The default value is 110.

inter-area dist2

(Optional) Sets the distance for all routes from one area to another area. The default value is 110.

external dist3

(Optional) Sets the distance for routes from other routing domains, learned by redistribution. The default value is 110.

intra-area dist1	(Optional) Sets the distance for all routes within an area. The default value is 110.
inter-area dist2	(Optional) Sets the distance for all routes from one area to another area. The default value is 110.
external dist3	(Optional) Sets the distance for routes from other routing domains, learned by redistribution. The default value is 110.

ignore lsa mospf

To suppress the sending of syslog messages when the router receives LSA Type 6 (MOSPF) packets, which are unsupported, use the ignore lsa mospf router configuration command. To restore the sending of syslog messages, use the no form of this command.

ignore lsa mospf

no ignore lsa mospf

Syntax Description

This command has no arguments or keywords.

ip ospf authentication

To specify the authentication type for an interface, use the ip ospf authentication interface configuration command. To remove the authentication type for an interface, use the no form of this command.

ip ospf authentication [message-digest | null]

no ip ospf authentication

Syntax Description

message-digest

(Optional) Specifies that message-digest authentication will be used.

null

(Optional) No authentication is used. Useful for overriding password or message-digest authentication if configured for an interface.

message-digest	(Optional) Specifies that message-digest authentication will be used.
null	(Optional) No authentication is used. Useful for overriding password or message-digest authentication if configured for an interface.

ip ospf authentication-key

To assign a password to be used by neighboring routers that are using the OSPF simple password authentication, use the ip ospf authentication-key interface configuration command. To remove a previously assigned OSPF password, use the no form of this command.

ip ospf authentication-key password

no ip ospf authentication-key

Syntax Description

password

Any continuous string of characters that can be entered from the keyboard up to 8 bytes in length.

password	Any continuous string of characters that can be entered from the keyboard up to 8 bytes in length.

ip ospf cost

To explicitly specify the cost of sending a packet on an interface, use the ip ospf cost interface configuration command. To reset the path cost to the default value, use the no form of this command.

ip ospf cost cost

no ip ospf cost

Syntax Description

cost

Unsigned integer value expressed as the link state metric. It can be a value in the range 1 to 65535.

cost	Unsigned integer value expressed as the link state metric. It can be a value in the range 1 to 65535.

ip ospf database-filter

To filter outgoing LSAs to an OSPF interface, use the ip ospf database-filter interface configuration command. To restore the forwarding of LSAs to the interface, use the no form of this command.

ip ospf database-filter all out

no ip ospf database-filter all out

Syntax Description

This command has no arguments or keywords.

ip ospf dead-interval

To set the interval at which hello packets must not be seen before neighbors declare the router down, use the ip ospf dead-interval interface configuration command. To return to the default time, use the no form of this command.

ip ospf dead-interval seconds

no ip ospf dead-interval

Syntax Description

seconds

Unsigned integer that specifies the interval in seconds; the value must be the same for all nodes on the network.

seconds	Unsigned integer that specifies the interval in seconds; the value must be the same for all nodes on the network.

ip ospf demand-circuit

To configure OSPF to treat the interface as an OSPF demand circuit, use the ip ospf demand-circuit interface configuration command. To remove the demand circuit designation from the interface, use the no form of this command.

ip ospf demand-circuit

no ip ospf demand-circuit

Syntax Description

This command has no arguments or keywords.

ip ospf hello-interval

To specify the interval between hello packets that the Cisco IOS software sends on the interface, use the ip ospf hello-interval interface configuration command. To return to the default time, use the no form of this command.

ip ospf hello-interval seconds

no ip ospf hello-interval

Syntax Description

seconds

Unsigned integer that specifies the interval in seconds. The value must be the same for all nodes on a specific network.

seconds	Unsigned integer that specifies the interval in seconds. The value must be the same for all nodes on a specific network.

ip ospf message-digest-key

To enable OSPF MD5 authentication, use the ip ospf message-digest-key interface configuration command. To remove an old MD5 key, use the no form of this command.

ip ospf message-digest-key keyid md5 key

no ip ospf message-digest-key keyid

Syntax Description

keyid

An identifier in the range 1 to 255.

key

Alphanumeric password of up to 16 bytes.

keyid	An identifier in the range 1 to 255.
key	Alphanumeric password of up to 16 bytes.

ip ospf name-lookup

To configure OSPF to look up Domain Name System (DNS) names for use in all OSPF show EXEC command displays, use the ip ospf name-lookup global configuration command. To disable this function, use the no form of this command.

ip ospf name-lookup

no ip ospf name-lookup

Syntax Description

This command has no arguments or keywords.

ip ospf network

To configure the OSPF network type to a type other than the default for a given media, use the ip ospf network interface configuration command. To return to the default value, use the no form of this command.

ip ospf network {broadcast | non-broadcast | {point-to-multipoint [non-broadcast] | point-to-point}}

no ip ospf network

Syntax Description

broadcast

Sets the network type to broadcast.

non-broadcast

Sets the network type to NBMA.

point-to-multipoint [non-broadcast]

Sets the network type to point-to-multipoint.

The optional non-broadcast keyword sets the point-to-multipoint network to be nonbroadcast. If you use the non-broadcast keyword, the neighbor command is required.

point-to-point

Sets the network type to point-to-point.

broadcast	Sets the network type to broadcast.
non-broadcast	Sets the network type to NBMA.
point-to-multipoint [non-broadcast]	Sets the network type to point-to-multipoint. The optional non-broadcast keyword sets the point-to-multipoint network to be nonbroadcast. If you use the non-broadcast keyword, the neighbor command is required.
point-to-point	Sets the network type to point-to-point.

ip ospf priority

To set the router priority, which helps determine the designated router for this network, use the ip ospf priority interface configuration command. To return to the default value, use the no form of this command.

ip ospf priority number

no ip ospf priority

Syntax Description

number

8-bit unsigned integer that specifies the priority. The range is from 0 to 255.

number	8-bit unsigned integer that specifies the priority. The range is from 0 to 255.

ip ospf retransmit-interval

To specify the time between link-state advertisement (LSA) retransmissions for adjacencies belonging to the interface, use the ip ospf retransmit-interval interface configuration command. To return to the default value, use the no form of this command.

ip ospf retransmit-interval seconds

no ip ospf retransmit-interval

Syntax Description

seconds

Time in seconds between retransmissions. It must be greater than the expected round-trip delay between any two routers on the attached network. The range is 1 to 65535 seconds. The default is 5 seconds.

seconds	Time in seconds between retransmissions. It must be greater than the expected round-trip delay between any two routers on the attached network. The range is 1 to 65535 seconds. The default is 5 seconds.

ip ospf transmit-delay

To set the estimated time it takes to transmit a link state update packet on the interface, use the ip ospf transmit-delay interface configuration command. To return to the default value, use the no form of this command.

ip ospf transmit-delay seconds

no ip ospf transmit-delay

Syntax Description

seconds

Time in seconds that it takes to transmit a link state update. The range is 1 to 65535 seconds. The default is 1 second.

seconds	Time in seconds that it takes to transmit a link state update. The range is 1 to 65535 seconds. The default is 1 second.

log-adj-changes

To configure the router to send a syslog message when the state of an OSPF neighbor changes, use the log-adj-changes router configuration command. To turn off this function, use the no form of this command.

log-adj-changes

no log-adj-changes

Syntax Description

This command has no arguments or keywords.

neighbor (OSPF)

To configure OSPF routers interconnecting to nonbroadcast networks, use this form of the neighbor router configuration command. To remove a configuration, use the no form of this command.

neighbor ip-address [priority number] [poll-interval seconds] [cost number] [database-filter [all]]

no neighbor ip-address [priority number] [poll-interval seconds] [cost number] [database-filter [all]]

Syntax Description

ip-address

Interface IP address of the neighbor.

priority number

(Optional) 8-bit number indicating the router priority value of the nonbroadcast neighbor associated with the IP address specified. The default is 0. This keyword does not apply to point-to-multipoint interfaces.

poll-interval seconds

(Optional) Unsigned integer value reflecting the poll interval. RFC 1247 recommends that this value be much larger than the hello interval. The default is 120 seconds (2 minutes). This keyword does not apply to point-to-multipoint interfaces.

cost number

(Optional) Assigns a cost to the neighbor, in the form of an integer from 1 to 65535. Neighbors with no specific cost configured will assume the cost of the interface, based on the ip ospf cost command. On point-to-multipoint interfaces, this is the only keyword and argument that make sense. This keyword does not apply to NBMA networks.

database-filter

(Optional) Filters outgoing LSAs to an OSPF neighbor.

ip-address	Interface IP address of the neighbor.
priority number	(Optional) 8-bit number indicating the router priority value of the nonbroadcast neighbor associated with the IP address specified. The default is 0. This keyword does not apply to point-to-multipoint interfaces.
poll-interval seconds	(Optional) Unsigned integer value reflecting the poll interval. RFC 1247 recommends that this value be much larger than the hello interval. The default is 120 seconds (2 minutes). This keyword does not apply to point-to-multipoint interfaces.
cost number	(Optional) Assigns a cost to the neighbor, in the form of an integer from 1 to 65535. Neighbors with no specific cost configured will assume the cost of the interface, based on the ip ospf cost command. On point-to-multipoint interfaces, this is the only keyword and argument that make sense. This keyword does not apply to NBMA networks.
database-filter	(Optional) Filters outgoing LSAs to an OSPF neighbor.

neighbor database-filter

To filter outgoing LSAs to an OSPF neighbor, use the neighbor database-filter router configuration command. To restore the forwarding of LSAs to the neighbor, use the no form of this command.

neighbor ip-address database-filter all out

no neighbor ip-address database-filter all out

Syntax Description

ip-address all out

IP address of the neighbor to which outgoing LSAs are blocked.

ip-address all out	IP address of the neighbor to which outgoing LSAs are blocked.

network area

To define the interfaces on which OSPF runs and to define the area ID for those interfaces, use the network area router configuration command. To disable OSPF routing for interfaces defined with the address wildcard-mask pair, use the no form of this command.

network address wildcard-mask area area-id

no network address wildcard-mask area area-id

Syntax Description

address

IP address.

wildcard-mask

IP-address-type mask that includes "don't care" bits.

area-id

Area that is to be associated with the OSPF address range. It can be specified as either a decimal value or as an IP address. If you intend to associate areas with IP subnets, you can specify a subnet address as the area-id.

address	IP address.
wildcard-mask	IP-address-type mask that includes "don't care" bits.
area-id	Area that is to be associated with the OSPF address range. It can be specified as either a decimal value or as an IP address. If you intend to associate areas with IP subnets, you can specify a subnet address as the area-id.

router ospf

To configure an OSPF routing process, use the router ospf global configuration command. To terminate an OSPF routing process, use the no form of this command.

router ospf process-id

no router ospf process-id

Syntax Description

process-id

Internally used identification parameter for an OSPF routing process. It is locally assigned and can be any positive integer. A unique value is assigned for each OSPF routing process.

process-id	Internally used identification parameter for an OSPF routing process. It is locally assigned and can be any positive integer. A unique value is assigned for each OSPF routing process.

show ip ospf

To display general information about OSPF routing processes, use the show ip ospf EXEC command.

show ip ospf [process-id]

Syntax Description

process-id

(Optional) Process ID. If this argument is included, only information for the specified routing process is included.

process-id	(Optional) Process ID. If this argument is included, only information for the specified routing process is included.

show ip ospf border-routers

To display the internal OSPF routing table entries to an area border router (ABR) and autonomous system boundary router (ASBR), use the show ip ospf border-routers privileged EXEC command.

show ip ospf border-routers

Syntax Description

This command has no arguments or keywords.

show ip ospf database

To display lists of information related to the OSPF database for a specific router, use the show ip ospf database EXEC command . The various forms of this command deliver information about different OSPF link state advertisements.

Syntax Description

process-id

(Optional) Internal identification. It is locally assigned and can be any positive integer. The number used here is the number assigned administratively when enabling the OSPF routing process.

area-id

(Optional) Area number associated with the OSPF address range defined in the network router configuration command used to define the particular area.

link-state-id

(Optional) Portion of the Internet environment that is being described by the advertisement. The value entered depends on the advertisement's LS type. It must be entered in the form of an IP address.

When the link state advertisement is describing a network, the link-state-id can take one of two forms:

The network's IP address (as in type 3 summary link advertisements and in autonomous system external link advertisements).

A derived address obtained from the link state ID. (Note that masking a network links advertisement's link state ID with the network's subnet mask yields the network's IP address.)

When the link state advertisement is describing a router, the link state ID is always the described router's OSPF router ID.

When an autonomous system external advertisement (LS Type = 5) is describing a default route, its link state ID is set to Default Destination (0.0.0.0).

adv-router [ip-address]

(Optional) Displays all the LSAs of the specified router. If no IP address is included, the information is about the local router itself (in this case, the same as self-originate).

asbr-summary

(Optional) Displays information only about the autonomous system boundary router summary LSAs.

database-summary

(Optional) Displays how many of each type of LSA for each area there are in the database, and the total.

external

(Optional) Displays information only about the external LSAs.

network

(Optional) Displays information only about the network LSAs.

nssa-external

(Optional) Displays information only about the NSSA external LSAs.

opaque-area

(Optional) Displays information about the opaque Type 10 LSAs. Type 10 denotes an area-local scope. Refer to RFC 2370 for more information on the opaque LSA options.

opaque-as

(Optional) Displays information about the opaque Type 11 LSAs. Type 11 denotes that the LSA is flooded throughout the autonomous system (AS).

opaque-link

(Optional) Displays information about the opaque Type 9 LSAs. Type 9 denotes a link-local scope.

router

(Optional) Displays information only about the router LSAs.

self-originate

(Optional) Displays only self-originated LSAs (from the local router).

summary

(Optional) Displays information only about the summary LSAs.

show ip ospf flood-list

To display a list of OSPF link state advertisements (LSAs) waiting to be flooded over an interface, use the show ip ospf flood-list EXEC command.

show ip ospf flood-list interface type number

Syntax Description

interface type number

Interface type and number over which the LSAs will be flooded.

show ip ospf interface

To display OSPF-related interface information, use the show ip ospf interface EXEC command.

show ip ospf interface [type number]

Syntax Description

type

(Optional) Interface type.

number

(Optional) Interface number.

show ip ospf neighbor

To display OSPF-neighbor information on a per-interface basis, use the show ip ospf neighbor EXEC command.

show ip ospf neighbor [type number] [neighbor-id] [detail]

Syntax Description

type

(Optional) Interface type.

number

(Optional) Interface number.

neighbor-id

(Optional) Neighbor ID.

detail

(Optional) Displays all neighbors given in detail (list all neighbors).

show ip ospf request-list

To display a list of all link state advertisements (LSAs) requested by a router, use the show ip ospf request-list EXEC command.

show ip ospf request-list [nbr] [intf] [intf-nbr]

Syntax Description

nbr

(Optional) Neighbor. Displays the list of all LSAs requested by the router from this neighbor.

intf

(Optional) Interface. Displays the list of all LSAs requested by the router from this interface.

intf-nbr

(Optional) Displays the list of all LSAs requested by the router on this interface from this neighbor.

show ip ospf retransmission-list

To display a list of all link state advertisements (LSAs) waiting to be retransmitted, use the show ip ospf retransmission-list EXEC command.

show ip ospf retransmission-list [nbr] [intf] [intf-nbr]

Syntax Description

nbr

(Optional) Neighbor. Displays the list of all LSAs waiting to be retransmitted for this neighbor.

intf

(Optional) Interface. Displays the list of all LSAs waiting to be retransmitted on this interface.

intf-nbr

(Optional) Displays the list of all LSAs waiting to be retransmitted on this interface from this neighbor.

show ip ospf virtual-links

To display parameters and the current state of OSPF virtual links, use the show ip ospf virtual-links EXEC command.

show ip ospf virtual-links

Syntax Description

This command has no arguments or keywords.

summary-address (OSPF)

To create aggregate addresses for OSPF, use the summary-address router configuration command. The no summary-address command restores the default.

summary-address address mask prefix mask [not-advertise] [tag tag]

no summary-address address mask

Syntax Description

address

Summary address designated for a range of addresses.

mask

IP subnet mask used for the summary route.

prefix

IP route prefix for the destination.

mask

IP subnet mask used for the summary route.

not-advertise

(Optional) Used to suppress routes that match the prefix/mask pair. This keyword applies to OSPF only.

tag tag

(Optional) Tag value that can be used as a "match" value for controlling redistribution via route maps. This keyword applies to OSPF only.

timers lsa-group-pacing

To change the interval at which OSPF LSAs are collected into a group and refreshed, checksummed, or aged, use the timers lsa-group-pacing router configuration command. To restore the default value, use the no form of this command.

timers lsa-group-pacing seconds

no timers lsa-group-pacing

Syntax Description

seconds

Number of seconds in the interval at which LSAs are grouped and refreshed, checksummed, or aged. The range is 10 seconds to 1800 seconds. The default value is 240 seconds.

timers spf

To configure the delay time between when OSPF receives a topology change and when it starts a shortest path first (SPF) calculation, and the hold time between two consecutive SPF calculations, use the timers spf router configuration command. To return to the default timer values, use the no form of this command.

timers spf spf-delay spf-holdtime

no timers spf spf-delay spf-holdtime

Syntax Description

spf-delay

Delay time, in seconds, between when OSPF receives a topology change and when it starts a SPF. calculation. It can be an integer from 0 to 65535. The default time is 5 seconds. A value of 0 means that there is no delay; that is, the SPF calculation is started immediately.

spf-holdtime

Minimum time, in seconds, between two consecutive SPF calculations. It can be an integer from 0 to 65535. The default time is 10 seconds. A value of 0 means that there is no delay; that is, two consecutive SPF calculations can be done one immediately after the other.

process-id	(Optional) Internal identification. It is locally assigned and can be any positive integer. The number used here is the number assigned administratively when enabling the OSPF routing process.
area-id	(Optional) Area number associated with the OSPF address range defined in the network router configuration command used to define the particular area.
link-state-id	(Optional) Portion of the Internet environment that is being described by the advertisement. The value entered depends on the advertisement's LS type. It must be entered in the form of an IP address. When the link state advertisement is describing a network, the link-state-id can take one of two forms: The network's IP address (as in type 3 summary link advertisements and in autonomous system external link advertisements). A derived address obtained from the link state ID. (Note that masking a network links advertisement's link state ID with the network's subnet mask yields the network's IP address.) When the link state advertisement is describing a router, the link state ID is always the described router's OSPF router ID. When an autonomous system external advertisement (LS Type = 5) is describing a default route, its link state ID is set to Default Destination (0.0.0.0).
adv-router [ip-address]	(Optional) Displays all the LSAs of the specified router. If no IP address is included, the information is about the local router itself (in this case, the same as self-originate).
asbr-summary	(Optional) Displays information only about the autonomous system boundary router summary LSAs.
database-summary	(Optional) Displays how many of each type of LSA for each area there are in the database, and the total.
external	(Optional) Displays information only about the external LSAs.
network	(Optional) Displays information only about the network LSAs.
nssa-external	(Optional) Displays information only about the NSSA external LSAs.
opaque-area	(Optional) Displays information about the opaque Type 10 LSAs. Type 10 denotes an area-local scope. Refer to RFC 2370 for more information on the opaque LSA options.
opaque-as	(Optional) Displays information about the opaque Type 11 LSAs. Type 11 denotes that the LSA is flooded throughout the autonomous system (AS).
opaque-link	(Optional) Displays information about the opaque Type 9 LSAs. Type 9 denotes a link-local scope.
router	(Optional) Displays information only about the router LSAs.
self-originate	(Optional) Displays only self-originated LSAs (from the local router).
summary	(Optional) Displays information only about the summary LSAs.

type	(Optional) Interface type.
number	(Optional) Interface number.

nbr	(Optional) Neighbor. Displays the list of all LSAs requested by the router from this neighbor.
intf	(Optional) Interface. Displays the list of all LSAs requested by the router from this interface.
intf-nbr	(Optional) Displays the list of all LSAs requested by the router on this interface from this neighbor.

address	Summary address designated for a range of addresses.
mask	IP subnet mask used for the summary route.
prefix	IP route prefix for the destination.
mask	IP subnet mask used for the summary route.
not-advertise	(Optional) Used to suppress routes that match the prefix/mask pair. This keyword applies to OSPF only.
tag tag	(Optional) Tag value that can be used as a "match" value for controlling redistribution via route maps. This keyword applies to OSPF only.

spf-delay	Delay time, in seconds, between when OSPF receives a topology change and when it starts a SPF. calculation. It can be an integer from 0 to 65535. The default time is 5 seconds. A value of 0 means that there is no delay; that is, the SPF calculation is started immediately.
spf-holdtime	Minimum time, in seconds, between two consecutive SPF calculations. It can be an integer from 0 to 65535. The default time is 10 seconds. A value of 0 means that there is no delay; that is, two consecutive SPF calculations can be done one immediately after the other.

Table of Contents

OSPF Commands