OSPF commands

ospf

Syntax

[no] ospf

Context

config>service>vprn

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

Commands in this context configure OSPF parameters for VPRN.

When an OSPF instance is created, the protocol is enabled. To start or suspend execution of the OSPF protocol without affecting the configuration, use the no shutdown command.

The no form of this command deletes the OSPF protocol instance and removes all associated configuration parameters.

Default

no ospf

area

Syntax

[no] area area-id

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures an OSPF area. An area is a collection of network segments within an AS that have been administratively grouped together. The area ID can be specified in dotted-decimal notation or as a 32-bit decimal integer.

The no form of this command deletes the specified area from the configuration. Deleting the area also removes the OSPF configuration of all the interfaces, virtual-links, sham-links, address-ranges, and so on, that are currently assigned to this area.

Default

no area

Parameters

area-id

Specifies the OSPF area ID expressed in dotted-decimal notation or as a 32-bit decimal integer.

Values

0.0.0.0 to 255.255.255.255 (dotted-decimal)

0 to 4294967295 (decimal integer)

area-range

Syntax

area-range ip-prefix/prefix-length [advertise | not-advertise]

no area-range ip-prefix/mask

no area-range ip-prefix/mask

Context

config>service>vprn>ospf>area

ospf>service>vprn>nssa

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command creates ranges of addresses on an Area Border Router (ABR) for the purpose of route summarization or suppression. When created, a range is configured to be advertised or not advertised into other areas. Multiple range commands may be used to summarize or hide different ranges. In the case of overlapping ranges, the most specific range command applies.

ABRs send summary link advertisements to describe routes to other areas. To minimize the number of advertisements that are flooded, you can summarize a range of IP addresses and send reachability information about these addresses in an LSA.

The no form of this command deletes the range advertisement or non-advertisement.

Default

no area-range

Special Cases

NSSA Context

In the NSSA context, the option specifies that the range applies to external routes (via type-7 LSAs) learned within the NSSA when the routes are advertised to other areas as type-5 LSAs.

Area Context

If this command is not entered under the NSSA context, the range applies to summary LSAs even if the area is an NSSA.

Parameters

ipv6-prefix/prefix-length

Specifies the IP prefix in dotted-decimal notation for the range used by the ABR to advertise the area into another area.

Values

ipv6-prefix:

x:x:x:x:x:x:x:x (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x: [0 to FFFF]H

d: [0 to 255]D

prefix-length:

0 to 128

mask

Specifies the subnet mask for the range expressed as a decimal integer mask length or in dotted-decimal notation.

Values

0 to 32 (mask length)

0.0.0.0 to 255.255.255.255 (dotted-decimal)

advertise | not-advertise

Keywords that specify whether to advertise the summarized range of addresses to other areas.

Default

advertise

blackhole-aggregate

Syntax

[no] blackhole-aggregate

Context

config>service>vprn>ospf>area

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command installs a low priority blackhole route for the entire aggregate. Existing routes that make up the aggregate have a higher priority and only the components of the range for which no route exists are blackholed.

When performing area aggregation, addresses may be included in the range for which no actual route exists. This can cause routing loops. To avoid this problem, configure the blackhole aggregate option.

The no form of this command removes this option.

Default

blackhole-aggregate

interface

Syntax

[no] interface ip-int-name [secondary]

Context

config>service>vprn>ospf>area

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures an OSPF interface.

By default, interfaces are not activated in any interior gateway protocol, such as OSPF, unless explicitly configured.

The no form of this command deletes the OSPF interface configuration for this interface. The shutdown command in the config>router>ospf>interface context can be used to disable an interface without removing the configuration for the interface.

Default

no interface

Parameters

ip-int-name

Specifies the IP interface name. Interface names must be unique within the group of defined IP interfaces for config router interface and config service vprn interface commands. An interface name cannot be in the form of an IP address. Interface names can be any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.

If the IP interface name does not exist or does not have an IP address configured, an error message is returned.

If the IP interface exists in a different area, it is moved to this area.

secondary

Keyword that allows multiple secondary adjacencies to be established over a single IP interface.

sham-link

Syntax

sham-link ip-int-name ip-address

Context

config>service>vprn>ospf>area

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command is similar to a virtual link with the exception that metric must be included to distinguish the cost between the MPLS-VPRN link and the backdoor.

Parameters

ip-int-name

Specifies the local interface name used for the sham-link. This is a mandatory parameter and interface names must be unique within the group of defined IP interfaces for config router interface, config service ies interface, and config service vprn interface commands. An interface name cannot be in the form of an IP address. Interface names can be any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters, the entire string must be enclosed within double quotes. If the IP interface name does not exist or does not have an IP address configured, an error message will be returned.

ip-address

Specifies the IP address of the sham-link neighbor in IP address dotted-decimal notation. This parameter is the remote peer of the sham-link IP address used to set up the sham link. This is a mandatory parameter and must be a valid IP address.

advertise-subnet

Syntax

[no] advertise-subnet

Context

config>service>vprn>ospf>area>if

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command enables advertising point-to-point interfaces as subnet routes (network number and mask). When disabled, point-to-point interfaces are advertised as host routes.

The no form of this command disables advertising point-to-point interfaces as subnet routes, meaning they are advertised as host routes.

Default

advertise-subnet

authentication-key

Syntax

authentication-key [authentication-key | hash-key] [hash | hash2]

no authentication-key

Context

config>service>vprn>ospf>area>if

config>service>vprn>ospf>area>virtual-link

config>service>vprn>ospf>area>sham-link

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the password used by the OSPF interface or virtual-link to send and receive OSPF protocol packets on the interface when simple password authentication is configured.

All neighboring routers must use the same type of authentication and password for correct protocol communication. If the authentication-type is configured as password, this key must be configured.

By default, no authentication key is configured.

The no form of this command removes the authentication key.

Default

no authentication-key

Parameters

authentication-key

Specifies the authentication key. The key can be any combination of ASCII characters up to 8 characters (unencrypted). If spaces are used in the string, enclose the entire string in quotation marks (‟ ”).

hash-key

Specifies the hash key. The key can be any combination of ASCII characters up to 22 characters (encrypted). If spaces are used in the string, enclose the entire string in quotation marks (‟ ”).

This is useful when a user must configure the parameter, but, for security purposes, the actual unencrypted key value is not provided.

hash

Keyword that specifies the key is entered in an encrypted form. If the hash parameter is not used, the key is assumed to be in a non-encrypted, clear text form. For security, all keys are stored in encrypted form in the configuration file with the hash parameter specified.

hash2

Keyword that specifies the key is entered in a more complex encrypted form. If the hash2 parameter is not used, the less encrypted hash form is assumed.

authentication-type

Syntax

authentication-type {password | message-digest}

no authentication-type

Context

config>service>vprn>ospf>area>if

config>service>vprn>ospf>area>virtual-link

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command enables authentication and specifies the type of authentication to be used on the OSPF interface, virtual-link, and sham-link.

Both simple password and message-digest authentication are supported.

By default, authentication is not enabled on an interface.

The no form of this command disables authentication on the interface.

Default

no authentication

Parameters

password

Keyword that enables simple password (plain text) authentication. If authentication is enabled and no authentication type is specified in the command, simple password authentication is enabled.

message-digest

Keyword that enables message digest MD5 authentication in accordance with RFC1321. If this option is configured, at least one message-digest-key must be configured.

bfd-enable

Syntax

bfd-enable [remain-down-on-failure]

no bfd-enable

Context

config>service>vprn>ospf>area>if

config>service>vprn>ospf>area>virtual-link

config>service>vprn>ospf>area>sham-link

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command enables the use of bidirectional forwarding (BFD) to control the state of the associated protocol interface. By enabling BFD on a specific protocol interface, the state of the protocol interface is tied to the state of the BFD session between the local node and the remote node. The parameters used for the BFD are set using the BFD command under the IP interface.

Note:
  • BFD is not supported for IPv6 interfaces.

  • See the 7210 SAS-Mxp, R6, R12, S, Sx, T Router Configuration Guide for more information about the protocols and platforms that support BFD.

The no form of this command removes BFD from the associated IGP protocol adjacency.

Default

no bfd-enable

Parameters

remain-down-on-failure

Keyword that forces adjacency down on BFD failure.

dead-interval

Syntax

dead-interval seconds

no dead-interval

Context

config>service>vprn>ospf>area>if

config>service>vprn>ospf>area>virtual-link

config>service>vprn>ospf>area>sham-link

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the time, in seconds, that OSPF waits before declaring a neighbor router down. If no hello packets are received from a neighbor for the duration of the dead interval, the router is assumed to be down. The minimum interval must be two times the hello interval.

The no form of this command reverts to the default value.

Default

40

Special Cases

OSPF Interface

If the dead-interval configured applies to an interface, all nodes on the subnet must have the same dead interval.

Virtual Like

If the dead-interval configured applies to a virtual link, the interval on both termination points of the virtual link must have the same dead interval.

Sham-link

If the dead-interval configured applies to a sham-link, the interval on both endpoints of the sham-link must have the same dead interval.

Parameters

seconds

Specifies the dead interval in seconds, expressed as a decimal integer.

Values

2 to 2147483647 seconds

hello-interval

Syntax

hello-interval seconds

no hello-interval

Context

config>service>vprn>ospf>area>if

config>service>vprn>ospf>area>virtual-link

config>service>vprn>ospf>area>sham-link

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the interval between OSPF hellos issued on the interface, virtual link, or sham-link.

The hello-interval, in combination with the dead-interval, is used to establish and maintain the adjacency. Use this parameter to edit the frequency that hello packets are sent.

Reducing the interval, in combination with a corresponding reduction in the associated dead-interval, allows for faster detection of link or router failures at the cost of higher processing costs.

The no form of this command reverts to the default value.

Default

hello-interval 10

Special Cases

OSPF Interface

If the hello-interval configured applies to an interface, all nodes on the subnet must have the same hello interval.

Virtual Link

If the hello-interval configured applies to a virtual link, the interval on both termination points of the virtual link must have the same hello interval.

Sham Link

If the hello-interval configured applies to a sham-link, the interval on both endpoints of the sham-link must have the same hello interval

Parameters

seconds

Specifies the hello interval in seconds, expressed as a decimal integer.

Values

1 to 65535

interface-type

Syntax

interface-type {broadcast | point-to-point}

no interface-type

Context

config>service>vprn>ospf>area>if

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the interface type to be either broadcast or point-to-point.

Use this command to set the interface type of an Ethernet link to point-to-point to avoid having to carry the broadcast adjacency maintenance overhead if the Ethernet link, provided the link is used as a point-to-point link.

If the interface type is not known at the time the interface is added to OSPF, and the subsequent IP interface is bound (or moved) to a different interface type, this command must be entered manually.

The no form of this command reverts to the default value.

Default

point-to-point — If the physical interface is SONET.

broadcast — If the physical interface is Ethernet or unknown.

Special Cases

Virtual-Link

A virtual link is always regarded as a point-to-point interface and is not configurable.

Parameters

broadcast

Keyword that configures the interface to maintain this link as a broadcast network. To significantly improve adjacency forming and network convergence, a network should be configured as point-to-point if only two routers are connected, even if the network is a broadcast media such as Ethernet.

point-to-point

Keyword that configures the interface to maintain this link as a point-to-point link.

message-digest-key

Syntax

message-digest-key keyid md5 [key | hash-key] [hash]

no message-digest-key keyid

Context

config>service>vprn>ospf>area>if

config>service>vprn>ospf>area>virtual-link

config>service>vprn>ospf>area>sham-link

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures a message digest key when MD5 authentication is enabled on the interface, virtual-link, or sham-link. Multiple message digest keys can be configured. By default, no message digest keys are defined.

The no form of this command removes the message digest key identified by the key-id.

Parameters

keyid

Specifies the key ID, expressed as a decimal integer.

Values

1 to 255

md5 key

Specifies the MD5 key. The key can be any alphanumeric string up to 16 characters.

md5 hash-key

Specifies the MD5 hash key. The key can be any combination of ASCII characters up to 32 characters (encrypted). If spaces are used in the string, enclose the entire string in quotation marks (‟ ”).

This is useful when a user must configure the parameter, but, for security purposes, the actual unencrypted key value is not provided.

hash

Keyword to specify that the key is entered in an encrypted form. If the hash parameter is not used, the key is assumed to be in a non-encrypted, clear text form. For security, all keys are stored in encrypted form in the configuration file, with the hash parameter specified.

metric

Syntax

metric metric

no metric

Context

config>service>vprn>ospf>area>if

config>service>vprn>ospf>area>sham-link

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures an explicit route cost metric for the OSPF interface that overrides the metrics calculated based on the speed of the underlying link.

The no form of this command deletes the manually configured interface metric, so the interface uses the computed metric based on the reference-bandwidth command setting and the speed of the underlying link.

Default

no metric

Parameters

metric

Specifies the metric to be applied to the interface, expressed as a decimal integer.

Values

1 to 65535

mtu

Syntax

mtu bytes

no mtu

Context

config>service>vprn>ospf>area>if

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the OSPF packet size used on the interface.

If this command is not configured, OSPF derives the MTU value from the MTU configured (default or explicitly) in the config>port>ethernet context.

If this parameter is configured, the smaller value between the value configured here and the MTU configured (default or explicitly) in a previously mentioned context is used.

To determine the actual packet size, add 14 bytes for an Ethernet packet and 18 bytes for a tagged Ethernet packet to the size of the OSPF (IP) packet MTU configured using this command.

The no form of this command reverts to default value.

Default

no mtu

Parameters

bytes

Specifies the MTU to be used by OSPF for this logical interface in bytes.

Values

512 to 9198 (9212 – 14) (depends on the physical media)

passive

Syntax

[no] passive

Context

config>service>vprn>ospf>area>if

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command adds the passive property to an OSPF interface.

By default, only interface addresses that are configured for OSPF are advertised as OSPF interfaces. The passive command allows an interface to be advertised as an OSPF interface without running the OSPF protocol.

While in passive mode, the interface ignores ingress OSPF protocol packets and does not transmit any OSPF protocol packets.

Service interfaces defined in the config>router>service-prefix context are passive. All other interfaces are not passive.

The no form of this command removes the passive property from the OSPF interface.

priority

Syntax

priority number

no priority

Context

config>service>vprn>ospf>area>if

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the priority of the OSPF interface that is used in an election of the designated router on the subnet.

This command is used only when the interface is of type broadcast. The router with the highest priority interface becomes the designated router. A router with priority 0 is not eligible to be a designated router or backup designated router.

The no form of this command reverts to the default value.

Default

priority 1

Parameters

number

Specifies the interface priority expressed as a decimal integer. A value of 0 indicates the router is not eligible to be the designated router or backup designated router on the interface subnet.

Values

0 to 255

retransmit-interval

Syntax

retransmit-interval seconds

no retransmit-interval

Context

config>service>vprn>ospf>area>if

config>service>vprn>ospf>area>virtual-link

config>service>vprn>ospf>area>sham-link

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command specifies the length of time, in seconds, that OSPF waits before retransmitting an unacknowledged Link State Advertisement (LSA) to an OSPF neighbor.

The value should be longer than the expected round trip delay between any two routers on the attached network. When the retransmit interval expires and no acknowledgment has been received, the LSA isretransmitted.

The no form of this command reverts to the default value.

Default

retransmit-interval 5

Parameters

seconds

Specifies the retransmit interval in seconds, expressed as a decimal integer.

Values

1 to 3600

transit-delay

Syntax

transit-delay seconds

no transit-delay

Context

config>service>vprn>ospf>area>if

config>service>vprn>ospf>area>virtual-link

config>service>vprn>ospf>area>sham-link

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the estimated time, in seconds, that it takes to transmit an LSA on the interface, virtual link, or sham-link.

The no form of this command reverts to the default value.

Default

transit-delay 1

Parameters

seconds

Specifies the transit delay in seconds, expressed as a decimal integer.

Values

0 to 3600

nssa

Syntax

[no] nssa

Context

config>service>vprn>ospf>area

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures an OSPF Not So Stubby Area (NSSA) and adds or removes the NSSA designation from the area.

NSSAs are similar to stub areas in that no external routes are imported into the area from other OSPF areas. The major difference between a stub area and an NSSA is an NSSA has the capability to flood external routes that it learns throughout its area and via an ABR to the entire OSPF domain.

Existing virtual links of a non-stub or NSSA area are removed when the designation is changed to NSSA or stub.

An area can be designated as stub or NSSA but never both at the same time.

By default, an area is not configured as an NSSA area.

The no form of this command removes the NSSA designation and configuration context from the area.

Default

no nssa

originate-default-route

Syntax

originate-default-route [type-7]

no originate-default-route

Context

config>service>vprn>ospf>area>nssa

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command enables the generation of a default route and its LSA type (3 or 7) into an NSSA by an NSSA Area Border Router (ABR).

When configuring an NSSA with no summaries, the ABR injects a type-3 LSA default route into the NSSA area. Some older implementations expect a type-7 LSA default route.

The no form of this command disables origination of a default route.

Default

no originate-default-route

Parameters

type-7

Keyword that specifies a type-7 LSA should be used for the default route.

Configure this parameter to inject a type-7 LSA default route instead of the type-3 LSA into the NSSA configured with no summaries. To revert to a type-3 LSA, enter originate-default-route without the type-7 parameter.

Default

type 3 LSA for the default route

redistribute-external

Syntax

[no] redistribute-external

Context

config>service>vprn>ospf>area>nssa

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command enables the redistribution of external routes into the NSSA or an NSSA ABR that is exporting the routes into non-NSSA areas.

NSSAs are similar to stub areas in that no external routes are imported into the area from other OSPF areas. The major difference between a stub area and an NSSA is that the NSSA has the capability to flood external routes that it learns (providing it is an ASBR) throughout its area and via an ABR to the entire OSPF domain.

The no form of this command disables the default behavior to automatically redistribute external routes into the NSSA area from the NSSA ABR.

Default

redistribute-external

summaries

Syntax

[no] summaries

Context

config>service>vprn>ospf>area>nssa

config>service>vprn>ospf>area>stub

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command enables sending summary (type-3) advertisements into a stub area or NSSA on an ABR.

This command is particularly useful to reduce the size of the routing and Link State Database (LSDB) tables within the stub or nssa area. By default, summary route advertisements are sent into the stub area or NSSA.

The no form of this command disables sending summary route advertisements and, for stub areas, only the default route is advertised by the ABR.

Default

summaries

stub

Syntax

[no] stub

Context

config>service>vprn>ospf>area

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures an OSPF stub area and adds or removes the stub designation from the area.

External routing information is not flooded into stub areas. All routers in the stub area must be configured with the stub command. An OSPF area cannot be both an NSSA and a stub area. Existing virtual links of a non-stub area or NSSA are removed when its designation is changed to NSSA or stub.

By default, an area is not a stub area.

The no form of this command removes the stub designation and configuration context from the area.

Default

no stub

default-metric

Syntax

default-metric metric

no default-metric

Context

config>service>vprn>ospf>area>stub

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the metric used by the ABR for the default route into a stub area.

The default metric should be configured only on an ABR of a stub area. An ABR generates a default route if the area is a stub area.

The no form of this command reverts to the default value.

Default

default-metric 1

Parameters

metric

Specifies the metric, expressed as a decimal integer, for the default route cost to be advertised into the stub area.

Values

1 to 16777215

virtual-link

Syntax

[no] virtual-link router-id transit-area area-id

Context

config>service>vprn>ospf>area

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures a virtual link to connect ABRs to the backbone.

The backbone area (area 0.0.0.0) must be contiguous and all other areas must be connected to the backbone area. If it is not practical to connect an area to the backbone (see area 0.0.0.2 in Figure: OSPF areas), the area border routers (routers 1 and 2 in Figure: OSPF areas) must be connected via a virtual link. The two area border routers form a point-to-point like adjacency across the transit area (area 0.0.0.1 in Figure: OSPF areas). A virtual link can be configured only while in the area 0.0.0.0 context.

The OSPF backbone area, area 0.0.0.0, must be contiguous and all other areas must be connected to the backbone area. The backbone distributes routing information between areas. If it is not practical to connect an area to the backbone (see area 0.0.0.5 in the following figure), the area border routers (such as routers Y and Z) must be connected via a virtual link. The two area border routers form a point-to-point-like adjacency across the transit area (see area 0.0.0.4).

Figure: OSPF areas

The router-id specified in this command must be associated with the virtual neighbor. The transit area cannot be a stub area or an NSSA.

The no form of this command deletes the virtual link.

Parameters

router-id

Specifies the router ID of the virtual neighbor, in IP address dotted-decimal notation.

transit-area area-id

Specifies the area ID for the transit area that links the backbone area with the area that has no physical connection with the backbone.

compatible-rfc1583

Syntax

[no] compatible-rfc1583

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command enables OSPF summary and external route calculations in compliance with RFC1583 and earlier RFCs.

RFC1583 and earlier RFCs use a different method to calculate summary and external route costs. To avoid routing loops, all routers in an OSPF domain should perform the same calculation method.

Although it would be favorable to require all routers to run a more current compliance level, this command allows the router to use obsolete methods of calculation.

The no form of this command enables the post-RFC1583 method of summary and external route calculation.

Default

compatible-rfc1583

export

Syntax

export policy-name [policy-name…]

no export

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command associates export route policies to determine which routes are exported from the route table to OSPF. Export polices are in effect only if OSPF is configured as an ASBR.

If no export policy is specified, non-OSPF routes are not exported from the routing table manager to OSPF.

If multiple policy names are specified, the policies are evaluated in the order they are specified. The first policy that matches is applied. If multiple export commands are issued, the last command entered overrides the previous command. A maximum of five policy names can be specified. The specified names must already be defined.

The no form of this command removes all policies from the configuration.

Default

no export

Parameters

policy-name

The export route policy name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.

external-db-overflow

Syntax

external-db-overflow limit seconds

no external-db-overflow

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures limits on the number of non-default AS-external LSA entries that can be stored in the link-state database (LSDB) and specifies a wait timer before processing these after the limit is exceeded.

The limit value specifies the maximum number of non-default AS-external LSA entries that can be stored in the LSDB. Placing a limit on the non-default AS-external LSAs in the LSDB protects the router from receiving an excessive number of external routes that consume excessive memory or CPU resources. If the number of routes reach or exceed the limit, the table is in an overflow state. When in an overflow state, the router will not originate any new AS-external LSAs and withdraws all the self-originated non-default external LSAs.

The seconds value specifies the amount of time to wait after an overflow state before regenerating and processing non-default, AS-external LSAs. The waiting period acts like a dampening period, preventing the router from continuously running shortest path first (SPF) calculations caused by the excessive number of non-default, AS-external LSAs.

The external-db-overflow command must be set identically on all routers attached to any regular OSPF area. OSPF stub areas and NSSAs are excluded.

The no form of this command disables limiting the number of non-default, AS-external LSA entries.

Default

no external-db-overflow

Parameters

limit

Specifies the maximum number of non-default, AS-external LSA entries that can be stored in the LSDB before going into an overflow state, expressed as a decimal integer.

Values

1 to 2147483647

seconds

Specifies the number of seconds after entering an overflow state before attempting to process non-default AS-external LSAs, expressed as a decimal integer.

Values

0 to 2147483647

external-preference

Syntax

external-preference preference

no external-preference

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the preference for OSPF external routes.

A route can be learned by the router from different protocols, in which case the costs are not comparable. When this occurs, the preference is used to decide which route is used.

Different protocols should not be configured with the same preference. If this occurs, the tiebreaker is based on the default preference table, as shown in the following table.

Table: Route preference defaults by route type
Route type Preference Configurable

Direct attached

0

No

Static routes

5

Yes

OSPF internal

10

Yes1

IS-IS level 1 internal

15

Yes

IS-IS level 2 internal

18

Yes

RIP

100

Yes

OSPF external

150

Yes

IS-IS level 1 external

160

Yes

IS-IS level 2 external

165

Yes

BGP

170

Yes

If multiple routes are learned with an identical preference using the same protocol, the lowest cost route is used. If multiple routes are learned with an identical preference using the same protocol and the costs (metrics) are equal, the decision of which route to use is determined by the configuration of the ecmp command in the config>router context

The no form of this command reverts to the default value.

Default

external-preference 150

Parameters

preference

Specifies the preference for external routes expressed as a decimal integer (see Table: Route preference defaults by route type).

Values

1 to 255

ignore-dn-bit

Syntax

[no] ignore-dn-bit

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command specifies whether to ignore the DN (down) bit for OSPF LSA packets for this instance of OSPF on the router. When enabled, the DN bit for OSPF LSA packets is ignored. When disabled, the DN bit is not ignored for OSPF LSA packets.

import

Syntax

import policy-name [policy-name...(up to 5 max)]

no import

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command specifies the import route policy that determines which routes are accepted from peers. Route policies are configured in the config>router>policy-options context.

This configuration parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific level is used.

When multiple policy names are specified, the policies are evaluated in the order they are specified. A maximum of five (5) policy names can be specified. The first policy that matches is applied.

When multiple import commands are issued, the last command entered overrides the previous command.

The no form of this command removes the policy association. To remove the association of all policies, use no import without arguments.

Default

no import

Parameters

policy-name

Specifies the route policy name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes.

overload

Syntax

overload [timeout seconds]

no overload

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command changes the overload state of the local router so that it appears to be overloaded. When overload is enabled, the router can participate in OSPF routing, but is not used for transit traffic. Traffic that is destined for directly attached interfaces continues to reach the router.

To put the IGP in an overload state, enter a timeout value. The IGP enters the overload state until the timeout timer expires or a no overload command is executed.

If the overload command is encountered during the execution of an command, this command takes precedence. This could occur as a result of a saved configuration file where both parameters are saved. When the file is saved by the system, the overload-on-boot command is saved after the overload command.

The no form of this command reverts to the default value. When the no overload command is executed, the overload state is terminated, regardless of the reason the protocol entered overload state.

Default

no overload

Parameters

timeout seconds

Specifies the number of seconds to reset overloading.

Values

60 to 1800

Default

60

overload-include-stub

Syntax

[no] overload-include-stub

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures whether the OSPF stub networks should be advertised with a maximum metric value when the system goes into an overload state for any reason. When enabled, the system uses the maximum metric value. When this command is enabled and the router is in overload, all stub interfaces, including loopback and system interfaces, are advertised at the maximum metric.

Default

no overload-include-stub

overload-on-boot

Syntax

overload-on-boot [timeout seconds]

no overload

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

When the router is in an overload state, the router is used only if there is no other router to reach the destination. This command configures the IGP upon bootup in the overload state until one of the following events occur:

  • the timeout timer expires

  • a manual override of the current overload state is entered with the no overload command

The no overload command does not affect the overload-on-boot function.

The no form of this command removes the overload-on-boot functionality from the configuration.

Default

no overload-on-boot

Parameters

timeout seconds

Specifies the number of seconds to reset overloading.

Values

60 to 1800

Default

60

preference

Syntax

preference preference

no preference

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the preference for OSPF internal routes.

A route can be learned by the router from different protocols, in which case the costs are not comparable. When this occurs, the preference is used to decide to which route is used.

Different protocols should not be configured with the same preference. If this occurs, the tiebreaker is based on the default preference table, as listed in Table: Route preference defaults by route type. If multiple routes are learned with an identical preference using the same protocol, the lowest cost route is used.

If multiple routes are learned with an identical preference using the same protocol and the costs (metrics) are equal, the decision of which route to use is determined by the configuration of the ecmp command in the config>router context.

The no form of this command reverts to the default value.

Default

preference 10

Parameters

preference

Specifies the preference for internal routes, expressed as a decimal integer. Table: Route preference defaults by route type lists the defaults for different route types.

Values

1 to 255

reference-bandwidth

Syntax

reference-bandwidth bandwidth-in-kbps

no reference-bandwidth

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the reference bandwidth used to calculate the default costs of interfaces based on their underlying link speed.

The default interface cost is calculated as follows:

cost = reference - bandwidth  bandwidth

The default reference bandwidth is 100,000,000 kb/s or 100 Gb/s; therefore, the default auto-cost metrics for various link speeds are as follows:

  • 10 Mb/s link default cost of 10000

  • 100 Mb/s link default cost of 1000

  • 1 Gb/s link default cost of 100

  • 10 Gb/s link default cost of 10

The reference-bandwidth command assigns a default cost to the interface based on the interface speed. To override this default cost on an interface, use the metric command in the config>router>ospf>area>interface ip-int-name context.

The no form of this command reverts the reference-bandwidth to the default value.

Default

reference-bandwidth 100000000

Parameters

bandwidth-in-kbps

Specifies the reference bandwidth in kilobits per second, expressed as a decimal integer.

Values

1 to 4000000000

super-backbone

Syntax

[no] super-backbone

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command specifies whether CE-PE functionality is required.

The OSPF super backbone indicates the type of the LSA generated as a result of routes redistributed into OSPF. When enabled, the redistributed routes are injected as summary, external, or NSSA LSAs. When disabled, the redistributed routes are injected as either external or NSSA LSAs only.

Default

no super-backbone

suppress-dn-bit

Syntax

[no] suppress-dn-bit

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command specifies whether to suppress the setting of the DN (down) bit for OSPF LSA packets generated by this instance of OSPF on the router. When enabled, the DN bit for OSPF LSA packets generated by this instance of the OSPF router is not set. When disabled, this instance of the OSPF router follows the normal procedure to determine whether to set the DN bit.

Default

no suppress-dn-bit

timers

Syntax

timers

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures OSPF timers. Timers control the delay between receipt of an LSA requiring an SPF calculation and the minimum time between successive SPF calculations.

Changing the timers affects CPU utilization and network reconvergence times. Lower values reduce convergence time but increase CPU utilization. Higher values reduce CPU utilization but increase reconvergence time.

spf-wait

Syntax

spf-wait max-spf-wait [spf-initial-wait [spf-second-wait]]

no spf-wait

Context

config>service>vprn>ospf>timers

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command defines the maximum interval between two consecutive SPF calculations. in milliseconds. Timers that determine when to initiate the first, second, and subsequent SPF calculations after a topology change occurs can be controlled with this command. Subsequent SPF runs (if required) occur at exponentially increasing intervals of the spf-second-wait interval. For example, if the spf-second-wait interval is 1000, the next SPF runs after 2000 milliseconds, and the next SPF runs after 4000 milliseconds, and so on, until it reaches the spf-wait value. The SPF interval stays at the spf-wait value until there are no more SPF runs scheduled in that interval. After a full interval without any SPF runs, the SPF interval drops back to spf-initial-wait.

The timer must be entered in increments of 100 milliseconds. Values entered that do not match this requirement are rejected.

The no form of this command reverts to the default value.

Default

no spf-wait

Parameters

max-spf-wait

Specifies the maximum interval, in milliseconds, between two consecutive SPF calculations.

Values

1 to 120000

Default

1000

spf-initial-wait

Specifies the initial SPF calculation delay, in milliseconds, after a topology change.

Values

10 to 100000

Default

1000

spf-second-wait

Specifies the hold time, in milliseconds, between the first and second SPF calculation.

Values

10 to 100000

Default

1000

vpn-domain

Syntax

vpn-domain id {0005 | 0105 | 0205 | 8005}

no vpn-domain

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command specifies the type of the extended community attribute exchanged using BGP to carry the OSPF VPN domain ID. This command applies to VPRN instances of OSPF only. An attempt to modify the value of this object results in an inconsistent value error when the instance is not a VPRN instance. The parameters are mandatory and can be entered in any order.

Default

no vpn-domain

Parameters

id

Specifies the OSPF VPN domain in the format ‟xxxx.xxxx.xxxx”. This ID is exchanged using BGP in the extended community attribute associated with a prefix. This object applies to VPRN instances of OSPF only.

0005 | 0105 | 0205 | 8005

Specifies the type of the extended community attribute exchanged using BGP to carry the OSPF VPN domain ID.

vpn-tag

Syntax

vpn-tag vpn-tag

no vpn-tag

Context

config>service>vprn>ospf

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command specifies the route tag for an OSPF VPN on a PE router. This field is set in the tag field of the OSPF external LSAs generated by the PE. This command is mainly used to prevent routing loops. This applies to VPRN instances of OSPF only. An attempt to modify the value of this object results in an inconsistent value error when the instance is not a VPRN instance.

Default

vpn-tag 0

Parameters

vpn-tag

Specifies the route tag for an OSPF VPN.

Default

0 to 4294967295

lsa-arrival

Syntax

lsa-arrival lsa-arrival-time

no lsa-arrival

Context

config>service>vprn>ospf>timers

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This parameter defines the minimum delay that must pass between receipt of the same LSAs arriving from neighbors.

Nokia recommends that the configured lsa-generate lsa-second-wait interval for the neighbors be equal or greater than the lsa-arrival-time.

The no form of this command reverts to the default value.

Default

no lsa-arrival

Parameters

lsa-arrival-time

Specifies the timer in milliseconds. Values entered that do not match this requirement are rejected.

Values

0 to 600000

lsa-generate

Syntax

lsa-generate max-lsa-wait [lsa-initial-wait [lsa-second-wait]]

no lsa-generate-interval

Context

config>service>vprn>ospf>timers

Platforms

Supported on all 7210 SAS platforms as described in this document

Description

This command configures the throttling of OSPF LSA generation. Timers that determine when to generate the first, second, and subsequent LSAs can be controlled with this command. Subsequent LSAs are generated at increasing intervals of the lsa-second-wait timer until a maximum value is reached. It is recommended that the lsa-arrival-time value be equal or less than the lsa-second-wait value configured in the lsa-generate command .

The no form of this command reverts to the default value.

Default

no lsa-generate

Parameters

max-lsa-wait

Specifies the maximum interval, in milliseconds, between two consecutive occurrences of an LSA being generated.

The timer must be entered as either 1 or in millisecond increments. Values entered that do not match this requirement are rejected.

Values

1 to 600000

1 Preference for OSPF internal routes is configured with the preference command.