This chapter describes how to configure the Open Shortest Path First (OSPF) Protocol. OSPF is an Interior Gateway Protocol (IGP). The router supports the following IGPs for building the IP routing table, Open Shortest Path First (OSPF) Protocol and RIP Protocol. OSPF is based on link-state technology or the shortest-path first (SPF) algorithm. RIP is based on the Bellman-Ford or the distance-vector algorithm. This chapter includes the following sections:
To access the OSPF configuration environment, enter the following command at the Config> prompt:
Config> protocol ospf Open SPF-based Routing Protocol configuration monitoring OSPF Config>
Before you can use OSPF, you must configure it using the OSPF configuration commands. The following section summarizes and then explains the OSPF commands.
| Note: | Except for the commands noted at Dynamically Changing OSPF Configuration Parameters, which cause OSPF to restart immediately with the changed parameters, the OSPF configuration commands are not effective immediately. They remain pending until you issue the Talk 5 reset ospf command. |
Table 67. OSPF Configuration Command Summary
| Command | Function |
|---|---|
| ? (Help) | Displays all the commands available for this command level or lists the options for specific commands (if available). See "Getting Help". |
| Add | Adds to already existent OSPF information. You can add ranges to areas, and neighbors to non-broadcast networks. |
| Delete | Deletes OSPF information from SRAM. |
| Disable | Disables the entire OSPF protocol, AS boundary routing capability, demand circuit capability. |
| Enable | Enables the entire OSPF protocol, AS boundary routing capability, demand circuit capability. |
| List | Displays OSPF configuration. |
| Set | Establishes or changes the configuration information concerning OSPF areas, interfaces, non-broadcast networks, or virtual links. This command also allows you to set the way in which OSPF routes are compared with information gained from other routing protocols. |
| Exit | Returns you to the previous command level. See "Exiting a Lower Level Environment". |
Except for the commands noted at Dynamically Changing OSPF Configuration Parameters, which cause OSPF to restart immediately with the changed parameters, the OSPF configuration (Talk 6) commands do not become effective immediately. They remain pending until you issue the Talk 5 reset ospf command.
Use the add command to add more information to already existing OSPF information. With this command you can add ranges to areas as well as neighbors to non-broadcast networks.
Syntax:
Ranges can be defined to control which routes are advertised externally to an area. There are two choices:
Ranges cannot be used for areas that serve as transit areas for virtual links. Also, when ranges are defined for an area, OSPF will not function correctly if the area is partitioned but is connected by the backbone.
Example:
add range 0.0.0.2 128.185.0.0 255.255.0.0
inhibit advertisement ? [No]
Valid Values: Any valid area number
Default Value: none
Valid Values: Any valid IP address.
Default Value: none
Valid Values: Any valid IP address mask.
Default Value: none
Example: add neighbor
Interface IP address [0.0.0.0]? 128.185.138.19
IP Address of Neighbor [0.0.0.0]? 128.185.138.21
Can that router become Designated Router on this net [Yes]?
Alternate TOS 0 cost [0]? 100
Valid Values: Any valid IP address.
Default Value: None
Valid Values: Any valid IP address
Default Value: None
Valid Values: Yes or No
Default Value: Yes
Valid Values: 0 - 65534
Default Value: 0 (indicates that interface cost should be used).
Use the delete command to delete OSPF information from SRAM.
Syntax:
Example: delete range 0.0.0.2 128.185.0.0 255.255.0.0
Valid Values: Any valid area address
Default Value: none
Valid Values: Any valid IP address.
Default Value: none
Valid Values: Any valid IP address mask.
Default Value: none
Example: delete area 0.0.0.1
Valid Values: Any valid area number.
Default Value: none
Example: delete interface 128.185.138.19
Valid Values: Any valid IP address.
Default Value: none
Example: delete neighbor
Interface IP address [0.0.0.0]? 128.185.138.19
IP Address of Neighbor [0.0.0.0]? 128.185.138.21
Valid Values: Any valid IP address.
Default Value: none
Valid Values: Any valid IP address.
Default Value: none
Example: delete non-broadcast 128.185.133.21
Valid Values: Any valid IP address.
Default Value: none
Example: delete virtual-link
Virtual endpoint (Router ID) [0.0.0.0]? 10.1.1.1
Link's transit area [0.0.0.1]? 0.0.0.2
Valid Values: Any valid IP address.
Default Value: none
Valid Values: Any valid area address.
Default Value: 0.0.0.1
Use the disable command to disable either the entire OSPF protocol or just the AS boundary routing capability.
Syntax:
Example: disable as boundary routing
Example: disable demand-circuits
Example: disable OSPF routing protocol
Example: disable rfc1583Compatibility
Example:
OSPF Config> disable subnet Interface IP address [0.0.0.0]? 8.24.3.1
Valid Values: Any valid IP address.
Default Value: none
Use the enable command to enable the OSPF protocol or particular aspects of that protocol, such as the advertisement of a stub to route to a subnet or the AS boundary routing capability.
Syntax:
Example:
Example 2:
enable as boundary routing Use route policy? [No]: Yes Router Policy Identifier [1-15 characters] [ ]? ospf-import Always originate default route? [No]:
Valid Values: yes or no
Default Value: no
Valid Values: a 1 to 15-character ASCII string
Default Value: none
Valid Values: Yes or No
Default Value: No
Valid Values: Yes or No
Default Value: No
Valid Values: Yes or No
Default Value: No
Valid Values: Yes or No
Default Value: No
Valid Values: Yes or No
Default Value: Yes
Valid Values: Yes or No
Default Value: No
Valid Values: 1 or 2
Default Value: 2
Valid Values: 0 to 16777215
Default Value: 1
Valid Values: a valid IP address
Default Value: none
OSPF Config> enable demand-circuits
Valid Values: 0 to 65535
Default Value: 100
Valid Values: 0 to 65535
Default Value: 50
Valid Values: 2048 to 65535
Default Value: 2048
Example: enable OSPF routing protocol
Estimated # external routes[100]? 200
Estimated # OSPF routers [50]? 60
Maximum LSA Size [2048]?
Example: enable rfc1583Compatibility
Example:
OSPF Config> enable subnet Interface IP address [0.0.0.0]? 8.24.3.1
Valid Values: Any valid IP address.
Default Value: none
Use the list command to display OSPF configuration information.
Syntax:
Example: list all
--Global configuration--
OSPF Protocol: Enabled
# AS ext. routes: 300
Estimated # routers: 100
Maximum LSA Size: 2048
External comparison: Type 2
RFC 1583 compatibility: Disabled
AS boundary capability: Enabled
Import external routes: BGP RIP STA DIR SUB
Orig. default route: No (0,0.0.0.0)
Default route cost: (1, Type 2)
Default forward. addr.: 0.0.0.0
Inter-area multicast: Enabled
Demand Circuits: Enabled
Least Cost Ranges: Disabled
LSA Max Random Initial Age: 0
--Area configuration--
Area ID AuType Stub? Default-cost Import-summaries?
0.0.0.0 0=None No N/A N/A
--Interface configuration--
IP address Area Cost Rtrns TrnsDly Pri Hello Dead
128.185.184.11 0.0.0.1 1 5 1 1 10 60
128.185.177.11 0.0.0.1 1 5 1 1 10 60
128.185.142.11 0.0.0.0 1 5 1 1 10 60
| OSPF protocol | Displays whether OSPF is enabled or disabled. |
| # AS ext. routes | Displays the estimated number of Autonomous System external routes. The router cannot accept more than this number of AS external routes. |
| Estimated # routers | Displays the estimated number of routers found in the OSPF configuration. |
| Maximum LSA size | Displays the maximum size LSA that will be originated by this router. |
| External comparison | Displays the external route type used by OSPF when importing external information into the OSPF domain and when comparing OSPF external routes to RIP/BGP routes. |
| RFC 1583 compatibility | Indicates whether or not OSPF AS external route is compatible with RFC 1583. |
| AS boundary capability | Displays whether the router will import external routes into the OSPF domain. |
| Import external | Displays which routes will be imported. |
| Orig default route | Displays whether the router will import a default into the OSPF domain. When the value is "YES", and a non-zero network number is displayed in parentheses. This indicates that the default route will be originated only if a route to that network is available. |
| Default route cost | Displays the cost and type that will be used in the imported default route. |
| Default forward addr | Displays the forwarding address that will be used for the originated default route. |
| Demand circuits | Displays whether demand circuit processing is supported. |
| External comparison | Displays the external route type used by OSPF when importing external information into the OSPF domain and when comparing OSPF external routes to RIP/BGP routes. |
| Inter-area multicast | Displays whether IP multicast datagrams will be forwarded between areas. |
| Area-ID | Displays the attached area ID (area summary information) |
| AuType | Displays the method used for area authentication. "Simple-pass" means a simple password scheme is being used for the area's authentication. |
| Stub area | Displays whether or not the area being summarized is a stub area. Stub areas do not carry external routes, resulting in a smaller routing database. However, stub areas cannot contain AS boundary routers, nor can they support configured virtual links. |
| OSPF interfaces | For each interface, its IP address is printed, together with configured parameters. "Area" is the OSPF area to which the interface attaches. "Cost" indicates the TOS 0 cost (or metric) associated with the interface. "Rtrns" is the retransmission interval, which is the number of seconds between retransmissions of unacknowledged routing information. "TrnsDly" is the transmission delay, which is an estimate of the number of seconds it takes to transmit routing information over the interface (it must be greater than 0). "Pri" is the interface's Router Priority, which is used when selecting the designated router. "Hello" is the number of seconds between Hello Packets sent out the interface. "Dead" is the number of seconds after Hellos cease to be heard that the router is declared down. |
| Virtual links | Lists all virtual links that have been configured with this router as end-point. "Virtual endpoint" indicates the OSPF Router ID of the other end-point. "Transit area" indicates the non-backbone area through which the virtual link is configured. Virtual links are considered treated by the OSPF protocol similarly to point-to-point networks. The other parameters listed in the command ("Rtrns", "TrnsDly", "Hello," and "Dead") are maintained for all interfaces. See the OSPF list interfaces command for more information. |
Example: list areas
--Area configuration--
Area ID AuType Stub? Default-cost Import-summaries?
0.0.0.0 0=None No N/A N/A
0.0.0.1 1=Simp-Pass No N/A N/A
| Area-ID | Displays the attached area ID (area summary information). |
| AuType | Displays the method used for area authentication. "Simple-pass" means a simple password scheme is being used for the area's authentication. |
| Stub area | Displays whether or not the area being summarized is a stub area. Stub areas do not carry external routes, resulting in a smaller routing database. However, stub areas cannot contain AS boundary routers, nor can they support configured virtual links. |
| Default-cost | For stub areas the cost of the default to be originated as an OSPF summary (type 3) Link State Advertisement (LSA). For transit areas (for example, non-stub areas), this field is N/A. |
| Import-summaries | For stub areas, indicates whether or not OSPF summary (type 3) Link State Advertisements are to be originated into the stub area. This question does not apply to the default summary. For transit areas (for example, non-stub areas, this field is N/A. |
Example: list interfaces
OSPF Config>list interface
--Interface configuration--
IP address Area Auth Cost Rtrns Delay Pri Hello Dead
200.1.1.2 0.0.0.2 0 10 5 1 1 10 40
10.69.1.2 0.0.0.0 1 1 5 1 1 10 40
OSPF Config>list virtual-link
--Virtual link configuration--
Virtual endpoint Transit area Auth Rtrns Delay Hello Dead
4.4.4.4 0.0.0.1 1 10 5 30 180
10.1.1.2 0.0.0.1 1 10 5 30 180
OSPF Config>
OSPF Config>list area
--Area configuration--
Area ID Stub? Default-cost Import-summaries?
0.0.0.2 No N/A N/A
0.0.0.0 No N/A N/A
0.0.0.1 No N/A N/A
0.0.0.3 Yes 10 Yes
| Note: | Multicast parameters are not displayed if multicast is disabled. Demand circuit parameters are not displayed if none of the interfaces are configured as demand circuits. |
Example: list neighbors
--Neighbor configuration--
Neighbor Addr Interface Address DR eligible? Alternate TOS 0 Cost
2.3.4.5 1.2.3.4 yes 0
2.5.6.7 5.6.7.8 no 100
Example: list non-broadcast
--NBMA configuration--
Interface Addr Poll Interval
128.185.235.34 120
Example: list virtual-links
--Virtual link configuration--
Virtual endpoint Transit area Rtrns TrnsDly Hello Dead
0.0.0.0 0.0.0.1 10 5 30 180
Use the set command to display or change the configuration information concerning OSPF areas, interfaces, non-broadcast networks, or virtual links. This command also allows you to set the way in which OSPF routes are compared to information obtained from other routing protocols.
Syntax:
Example: set area
Area number [0.0.0.0]? 0.0.0.1
Is this a stub area? [No]: yes
Stub default cost? [0]:
Import summaries? [Yes]:
External Routing in Stub Areas. You cannot configure the backbone as a stub area. External routing in stub areas is based on a default route. Each border area router that is attached to a stub area originates a default route for this purpose. The cost of this default route is also configurable with the set area command.
Example: set comparison
OSPF Config> set comparison
Compare to type 1 or 2 externals [2]?
Valid values: 1 to 65535 seconds
Default Value: 5
Each link-state advertisement has a finite lifetime that is equal to the constant MaxAge (1 hour). As each link-state advertisement is sent to the particular interfaces, it is aged by this configured transmission delay. The minimum delay is 1 second.
Valid Values: 1 to 65535 seconds
Default Value: 1
Valid Values: 1 to 65535 seconds
Default Value: 10
Dead Router Interval is the interval after which a router that has not sent a Hello will be considered dead. The Dead Router Interval defaults to four times the configured Hello Interval. The value for this parameter must be greater than the Hello Interval.
Valid Values: 2 to >= 65535 seconds
Default Value: 40 (or four times the configured Hello interval)
Valid Values: 0 to 255
Default Value: 1
Valid Values: 1 to 65534
Default Value: 1
Valid Values: Yes or No
Default Value: No
Valid Values: Allow, Request, or Disable
Default Value: Allow
Valid Values: 1 to 65535
Default Value: 60
Valid Values: 0, 1
Default Value: 0
Valid Values: any 1-8 characters
Default Value: a null string
Example: set interface
Interface IP address [0.0.0.0]? 10.69.1.2
Attaches to area [0.0.0.0]?
Retransmission Interval (in seconds) [5]?
Transmission Delay (in seconds) [1]? 1
Router Priority [1]? 1
Hello Interval (in seconds) [10]?
Dead Router Interval (in seconds) [40]?
Type Of Service 0 cost [1]?
Demand Circuit (Yes or NO) ?[No]:
Authentication Type (0 - none, 1 - simple) [0]? 1
Authentication Key []? AceeOSPF
Retype Auth. Key []? AceeOSPF
When responding to the prompts, supply the IP address for each interface in the router and answer the questions that follow. For the following parameters, you must enter the same value for all routers attached to a common network:
The first prompt asks for the OSPF area to which the interface attaches. For example, suppose that the interface address mask is 255.255.255.0, indicating that the interface attaches to a subnet (128.185.138.0) of network 128.185.0.0. All other OSPF routers attached to subnet 128.185.138.0 must also have their Hello interval set to 10, dead router interval set to 40, and their interface authentication key set to xyz_q.
Note that IP interfaces to point-to-point lines may be unnumbered. In this case a net index is configured instead of an IP address. This implementation of OSPF will work with these unnumbered interfaces, but to work correctly, both ends of the point-to-point line must use an unnumbered interface.
For Frame Relay or ATM networks, however, the set non-broadcast command is used to configure an OSPF interface as connecting to a non-broadcast multi-access network. If the set non-broadcast command is not used, the interface is assumed to be connected to a point-to-multipoint network. In Frame Relay networks, all OSPF interfaces must be configured as connecting to the same type of network (non-broadcast multi-access or point-to-multipoint), so if the set non-broadcast command is used for one router's interface, it must be configured on the interfaces for all routers attaching to the network.
Example: set non-broadcast
Interface IP address [0.0.0.0]? 128.185.138.19
Poll Interval [120]
Valid Values: Any valid IP address.
Default Value: none
Valid Values: 1 to 65535 seconds
Default Value: 120 seconds
Example: set non-broadcast
Interface IP address [0.0.0.0]? 128.185.138.19
Poll Interval [120]?
Virtual links can be configured between any two backbone routers that have an interface to a common non-backbone area. Virtual links are used to maintain backbone connectivity and must be configured at both end-points.
| Note: | This OSPF implementation supports the use of virtual links when one end of
the virtual link may be an unnumbered point to point line. For this
configuration to work, the router id must be used as the source address in
OSPF protocol messages sent over the virtual link. Use of the router id
can be insured by configuring the internal IP address with the address used as
the router id. Another requirement for this configuration to work is
that the OSPF implementations at both ends of the virtual link support
it.
|
Valid Values: any 1-8 characters
Default Value: a null string
Example: set virtual-link
Virtual endpoint (Router ID) [0.0.0.0]? 10.1.1.2
Link's transit area [0.0.0.1]?
Virtual link already exists - record will be modified.
Retransmission Interval (in seconds) [10]?
Transmission Delay (in seconds) [5]?
Hello Interval (in seconds) [30]?
Dead Router Interval (in seconds) [180]?
Authentication Type (0 - none, 1 - simple) [0] 1
Authentication Key []? AceeOSPF
Retype Auth. Key []? AceeOSPF
Use the following procedure to access the OSPF monitoring commands. This process gives you access to the OSPF monitoring process.
* talk 5
+
After you enter the talk 5 command, the GWCON prompt (+) displays on the terminal. If the prompt does not appear when you first enter configuration, press Return again.
Example:
+ prot ospf
OSPF>
This section summarizes and then explains all the OSPF monitoring commands. These commands enable you to monitor the OSPF routing protocol. Table 68 lists the OSPF monitoring commands.
Enter the OSPF monitoring commands at the OSPF>
prompt.
Table 68. OSPF Monitoring Command Summary
| Command | Function |
|---|---|
| ? (Help) | Displays all the commands available for this command level or lists the options for specific commands (if available). See "Getting Help". |
| Advertisement | Displays a link state advertisement belonging to the OSPF database. |
| Area summary | Displays OSPF area statistics and parameters. |
| AS external | Lists the AS external advertisements belonging to the OSPF link state database. |
| Database summary | Displays the advertisements belonging to an OSPF area's link state database. |
| Dump routing tables | Displays the OSPF routes contained in the routing table. |
| Interface summary | Displays OSPF interface statistics and parameters. |
| Neighbor summary | Displays OSPF neighbor statistics and parameters. |
| Ping | Continuously sends ICMP Echo Requests (or pings) a given destination, printing a line for each response received. |
| Policy | Displays any configured AS boundary router import policy. |
| Reset | Resets the OSPF configuration dynamically. |
| Routers | Displays the reachable OSPF area-border routers and AS-boundary routers. |
| Size | Displays the number of LSAs currently in the link state database, categorized by type. |
| Statistics | Displays OSPF statistics detailing memory and network usage. |
| Traceroute | Displays the complete route (hop-by-hop) to a given destination. |
| Weight | Dynamically changes the cost of an OSPF interface. |
| Exit | Returns you to the previous command level. See "Exiting a Lower Level Environment". |
Use the advertisement expansion command to print the contents of a link state advertisement contained in the OSPF database. For a summary of the router's advertisements use the database command.
A link state advertisement is defined by its link state type, link state ID and its advertising router. There is a separate link state database for each OSPF area. Providing an area-id on the command line tells the software which database you want to search. The different kinds of advertisements, which depend on the value given for link-state-type, are:
| Note: | Link State IDs, advertising routers (specified by their router IDs), and area IDs take the same format as IP addresses. For example, the backbone area can be entered as 0.0.0.0. |
Example 1 shows an expansion of a router links advertisement. The router's ID is 128.185.184.11. It is an AS boundary router and has three interfaces to the backbone area (all of cost 1). Detailed field descriptions are provided with the example.
This command has also been enhanced in two ways. First of all, when displaying router-LSAs and network-LSAs, the reverse cost of each router-to-router link and router-to-transit-network link is displayed, as well as the previously displayed forward cost. This is done because routing of multicast datagrams whose source lies in different areas/Autonomous systems is based on reverse cost instead of forward cost. In those cases where there is no reverse link (which means that the link will never be used by the Dijkstra), the reverse cost is shown as "1-way".
In addition, the LSA's OSPF options are displayed in the same manner as they were displayed in the detailed OSPF neighbor command.
New group-membership-LSAs can also be displayed. The "LS destination" of each group-membership-LSA is a group address. A router originates a group-membership-LSA for each group that has members on one or more of the router's attached networks. The group-membership-LSA for the group lists those attached transit networks having group members (the type "2" vertices), and when there are members belonging to one or more attached stub networks, or if the router itself is a member of the multicast group, a type "1" vertex whose ID is the router's OSPF router ID is included.
Syntax:
Example 1: advertisement 1 128.185.184.11 0.0.0.0
LS age: 173
LS options: E,MC,DC
LS type: 1
LS destination (ID): 128.185.184.11
LS originator: 128.185.184.11
LS sequence no: 0x80000047
LS checksum: 0x122
LS length: 60
Router type: ASBR,W
# router ifcs: 3
Link ID: 128.185.177.31
Link Data: 128.185.177.11
Interface type: 2
No. of metrics: 0
TOS 0 metric: 3 (0)
Link ID: 128.185.142.40
Link Data: 128.185.142.11
Interface type: 2
No. of metrics: 0
TOS 0 metric: 4 (0)
Link ID: 128.185.184.0
Link Data: 255.255.255.0
Interface type: 3
No. of metrics: 0
TOS 0 metric: 1
| LS age | Indicates the age of the advertisement in seconds. |
| LS options | Indicates the optional OSPF capabilities supported by the OSPF
object corresponding to the advertisement. These capabilities
include:
|
| LS type | Classifies the advertisement and dictates its contents: 1 (router links advertisement), 2 (network link advertisement), 3 (summary link advertisement), 4 (summary ASBR advertisement), 5 (AS external link) and 6 (group-membership advertisement). |
| LS destination | Identifies what is being described by the advertisement. Depends on the advertisement type. For router links and ASBR summaries, it is the OSPF router ID. For network links, it is the IP address of the network's designated router. For summary links and AS external links, it is a network/subnet number. For group-membership advertisements, it is a particular multicast group. |
| LS originator | OSPF router ID of the originating router. |
| LS sequence number | Used to distinguish separate instances of the same advertisement. Should be looked at as a signed 32-bit integer. Starts at 0x80000001, and increments by one each time the advertisement is updated. |
| LS checksum | A checksum of advertisement contents, used to detect data corruption. |
| LS length | The size of the advertisement in bytes. |
| Router type | Indicates the level of function of the router. ASBR means that the router is an AS boundary router, ABR that the router is an area border router, and W that the router is a wildcard multicast receiver. |
| # Router ifcs | The number of router interfaces described in the advertisement. |
| Link ID | Indicates what the interface connects to. Depends on Interface type. For interfaces to routers (i.e., point-to-point links), the Link ID is the neighbor's router ID. For interfaces to transit networks, it is the IP address of the network designated router. For interfaces to stub networks, it is the network's network/subnet number. |
| Link Data | 4 bytes of extra information concerning the link, it is either the IP address of the interface (for interfaces to point-to-point networks and transit networks), or the subnet mask (for interfaces to stub networks). |
| Interface type | One of the following: 1 (point-to-point connection to another router, 2 (connection to transit network), 3 (connection to stub network) or 4 (virtual link). |
| No. of metrics | The number of non-zero TOS values for which metrics are provided for this interface. |
| TOS 0 metric | The cost of the interface. In parenthesis the reverse cost of the link is given (derived from another advertisement). If there is no reverse link, "1-way" is displayed. |
The LS age, LS options, LS type, LS destination, LS originator, LS sequence no, LS checksum and LS length fields are common to all advertisements. The Router type and # router ifcs are seen only in router links advertisements. Each link in the router advertisement is described by the Link ID, Link Data, and Interface type fields. Each link can also be assigned a separate cost for each IP Type of Service (TOS); this is described by the No. of metrics and TOS 0 metric fields (the router currently does not route based on TOS, and looks at the TOS 0 cost only).
Example 2 shows an expansion of a group-membership advertisement. A group-membership advertisement for a given group/advertising router combination lists those networks directly attached to the advertising router which have group members. It also lists whether the router itself is a member of the specified group. The example below shows that network 128.185.184.0 has members of group 224.0.1.1.
Example 2: adv 6 224.0.1.1 128.185.184.114
For which area [0.0.0.0]?
LS age: 168
LS options: E
LS type: 6
LS destination (ID): 224.0.1.1
LS originator: 128.185.184.114
LS sequence no: 0x80000001
LS checksum: 0x7A3
LS length: 28
Vertex type: 2
Vertex ID: 128.185.184.114
| Vertex type | Describes the object having group members, one of: 1 (the router itself, or stub networks attached to the router) or 2 (a transit network). |
| Vertex ID | When the vertex type is 1, always the advertising router''s ID. When the vertex type is 2, the IP address of the transit network's designated router. |
Use the area summary command to display the statistics and parameters for all OSPF areas attached to the router.
In the example below, the router attaches to a single area (the backbone area). A simple password scheme is being used for the area's authentication. The router has three interfaces attaching to the area, and has found 4 transit networks, 7 routers and no area border routers when doing the SPF tree calculation for the backbone.
Syntax:
Example:
Area ID #ifcs #nets #rtrs #brdrs
0.0.0.1 1 1 2 2
0.0.0.0 3 0 3 2
| # ifcs | Indicates the number of router interfaces attached to the particular area. These interfaces are not necessarily functional. |
| # nets | Indicates the number of transit networks that have been found while doing the SPF tree calculation for this area. |
| # rtrs | Indicates the number of routers that have been found when doing the SPF tree calculation for this area. |
| # brdrs | Indicates the number of area border routers that have been found when doing the SPF tree calculation for this area. |
Use the AS-external advertisements command to list the AS external advertisements belonging to the OSPF routing domain. One line is printed for each advertisement. Each advertisement is defined by the following three parameters: its link state type (always 5 for AS external advertisements), its link state ID (called the LS destination), and the advertising router (called the LS originator).
Syntax:
Example: as-external
Type LS-destination LS-originator Seq-Number Age Unreach Xsum Options
5 10.13.64.0 10.1.62.1 0x80000385 1422 0x7791 E,DC
5 10.14.64.0 10.1.62.1 0x80000385 1420 0x6B9C E,DC
# advertisements: 2
Checksum total: 0xE32D
| Type | Always 5 for AS external advertisements. |
| LS destination | Indicates an IP network/subnet number. These network numbers belong to other Autonomous Systems. |
| LS originator | Advertising router. |
| Unreach | Indicates how long the destination associated with a Link State Advertisement (LSA) that is DoNotAge has been unreachable. If the LSA is DoNotAge, DA will appear after the Age column before the Unreach column. If the LSA is not DoNotAge, there will be blanks. |
| Seqno, Age, Xsum | It is possible for several instances of an advertisement to be present in the OSPF routing domain at any one time. However, only the most recent instance is kept in the OSPF link state database (and printed by this command). The LS sequence number (Seqno), LS age (Age) and LS checksum fields (Xsum) are compared to see which instance is most recent. The LS age field is expressed in seconds. Its maximum value is 3600. |
| Options | These are the Link State Options, which are the optional OSPF
capabilities supported by the OSPF object corresponding to the
advertisement. These capabilities include:
|
At the end of the display, the total number of AS external advertisements is printed, along with a checksum total over all of their contents. The checksum total is simply the 32-bit sum (carries discarded) of the individual advertisement's LS checksum fields. This information can be used to quickly determine whether two OSPF routers have synchronized databases.
Use the database summary command to display a description of the contents of a particular OSPF area's link state database. AS external advertisements are omitted from the display. A single line is printed for each advertisement. Each advertisement is defined by the following three parameters: its link state type (called Type), its link state ID (called the LS destination) and the advertising router (called the LS originator).
Syntax:
Example: database 0.0.0.0
Type LS-destination LS-originator Seq-Number Age Unreach Xsum Options
1 10.1.62.1 10.1.62.1 0x80004963 496 0xBC15 E,DC
1 10.1.62.2 10.1.62.2 0x800250FF 6 0xCA6F E,DC
·
# advertisements: 99
Checksum total: 0x2CD102
| Type | Separate LS types are numerically displayed: type 1 (router links advertisements), type 2 (network links advertisements), type 3 (network summaries), type 4 (AS boundary router summaries), and type 6 (group-membership-LSAs). |
| LS destination | Indicates what is being described by the advertisement. |
| LS originator | Advertising router. |
| Unreach | Indicates how long the destination associated with a Link State Advertisement (LSA) that is DoNotAge has been unreachable. If the LSA is DoNotAge, DA will appear after the Age column before the Unreach column. If the LSA is not DoNotAge, there will be blanks. |
| Seqno, Age, Xsum | It is possible for several instances of an advertisement to be presenting the OSPF routing domain at any one time. However, only the most recent instance is kept in the OSPF link state database (and printed by this command). The LS sequence number (Seqno), LS age (Age) and LS checksum fields (Xsum) are compared to see which instance is most recent. The LS age field is expressed in seconds. Its maximum value is 3600. |
| Options | These are the Link State Options, which are the optional OSPF
capabilities supported by the OSPF object corresponding to the
advertisement. These capabilities include:
|
At the end of the display, the total number of advertisements in the area database is printed, along with a checksum total over all of their contents. The checksum total is simply the 32-bit sum (carries discarded) of the individual advertisement's LS checksum fields. This information can be used to quickly determine whether two OSPF routers have synchronized databases.
Use the dump routing tables command to display all the routes that have been calculated by OSPF and are now present in the routing table. Its output is similar in format to the IP monitoring's dump routing tables command.
Syntax:
Example: dump
Type Dest net Mask Cost Age Next hop(s)
SPE1 0.0.0.0 00000000 4 3 128.185.138.39
SPF* 128.185.138.0 FFFFFF00 1 1 Eth/0
Sbnt 128.185.0.0 FFFF0000 1 0 None
SPF 128.185.123.0 FFFFFF00 3 3 128.185.138.39
SPF 128.185.124.0 FFFFFF00 3 3 128.185.138.39
SPF 192.26.100.0 FFFFFF00 3 3 128.185.131.10
RIP 197.3.2.0 FFFFFF00 10 30 128.185.131.10
RIP 192.9.3.0 FFFFFF00 4 30 128.185.138.21
Del 128.185.195.0 FFFFFF00 16 270 None
Default gateway in use.
Type Cost Age Next hop
SPE1 4 3 128.185.138.39
Routing table size: 768 nets (36864 bytes), 36 nets known
| Type (route type) | Indicates how the route was derived.
Sbnt - Indicates that the network is subnetted; such an entry is a place-holder only. Dir - Indicates a directly connected network or subnet. RIP - Indicates the route was learned through the RIP protocol. Del - Indicates the route has been deleted. Stat - Indicates a statically configured route. BGP - Indicates routes learned through the BGP protocol. BGPR - Indicates routes learned through the BGP protocol that are readvertised by OSPF and RIP. Fltr - Indicates a routing filter. SPF - Indicates that the route is an OSPF intra-area route. SPIA - Indicates that it is an OSPF inter-area routes. SPE1, SPE2 - Indicates OSPF external routes (type 1 and 2 respectively). Rnge - Indicates a route type that is an active OSPF area address range and is not used in forwarding packets. |
| Dest net | IP destination network/subnet. |
| Mask | IP address mask. |
| Cost | Route Cost. |
| Age | For RIP and BGP routes, the time that has elapsed since the routing table entry was last refreshed. |
| Next Hop | IP address of the next router on the path toward the destination host. Also displayed is the interface type used by the sending router to forward the packet. |
An asterisk (*) after the route type indicates the route has a static or directly connected backup. A percent sign (%) after the route type indicates that RIP updates will always be accepted for this network/subnet.
A number in parentheses at the end of the column indicates the number of equal-cost routes to the destination. The first hops belonging to these routes can be displayed with the IP monitoring's route command.
Use the interface summary command to display statistics and parameters related to OSPF interfaces. If no arguments are given (see Example 1), a single line is printed summarizing each interface. If an interface's IP address is given (see Example 2), detailed statistics for that interface will be displayed.
Syntax:
Example 2: interface 128.185.125.22
Interface address: 128.185.125.22
Attached area: 0.0.0.1
Physical interface: Eth/1
Interface mask: 255.255.255.0
Interface type: Brdcst
State: 32
Authentication Type: None
Designated Router: 128.185.184.34
Backup DR: 128.185.184.11
DR Priority: 1 Hello interval: 10 Rxmt interval: 5
Dead interval: 40 TX delay: 1 Poll interval: 0
Demand Circuit off Max pkt size: 2044 TOS 0 cost: 1
# Neighbors: 0 # Adjacencies: 0 # Full adjs.: 0
| Interface Address | Interface IP address. |
| Attached Area | Attached area ID. |
| Physical interface | Displays physical interface type and number. |
| Interface Mask | Displays interface subnet mask. |
| Interface type | Can be either Brdcst (broadcast, e.g., an Ethernet interface), PP (a point-to-point network, e.g., a synchronous serial line), P-2-MP (point-to-multipoint, e.g., a Frame-Relay network), Multi (non-broadcast, multi-access, e.g., an X.25 connection) and VLink (an OSPF virtual link). |
| State | Can be one of the following: 1 (Down), 2 (Looped back), 4 (Waiting), 8 (Point-to-Point), 16 (DR other), 32 (Backup DR), 64 (Designated router) or 128 (Full). |
| Authentication Type | Indicates the type of authentication active for the interface. Supported types are none or simple. |
| Designated Router | IP address of the designated router. |
| Backup DR | IP address of the backup designated router. |
| DR Priority | Displays priority assigned to designated router. |
| Hello interval | Displays the current hello interval value. |
| Rxmt interval | Displays the current retransmission interval value. |
| Dead interval | Displays the current dead interval value. |
| TX delay | Displays the current transmission delay value. |
| Poll interval | Displays the current poll interval value. |
| Max pkt size | Displays the maximum size for an OSPF packet sent out this interface. |
| Demand circuit | Indicates whether or not demand circuit processing is active on the interface. |
| TOS 0 cost | Displays the interface's TOS 0 cost. |
| # Neighbors | Number of neighbors. This is the number of routers whose hellos have been received, plus those that have been configured. |
| # Adjacencies | Number of adjacencies. This is the number of neighbors in state Exchange or greater. |
| # Full adj | Number of full adjacencies. The number of full adjacencies is the number of neighbors whose state is Full (and therefore, with which the router has synchronized databases). |
| DL unicast | Displays whether multicast datagrams are to be forwarded as data-link multicasts or as data-link unicasts. |
| # MC data acc | Displays the number of multicast datagrams that have been successfully forwarded. |
| # MC data out | Displays the number of datagrams that have been forwarded out the interface (either as data-link multicasts or data-link unicasts). |
| Network Capabilities | Displays the network capabilities for the interface. |
| Nbr node: type and ID | Displays the identity of the upstream node if the router were supposed to receive datagrams on this interface. Type here is an integer from 1 to 3, with 1 indicating router, 2 indicating transit net and 3 indicating stub net. |
Use the neighbor command to display statistics and parameters related to OSPF neighbors. If no arguments are given (see Example 1), a single line is printed summarizing each neighbor. If a neighbor's IP address is given (see Example 2), detailed statistics for that neighbor will be displayed.
Syntax:
Example 1: neighbor
Neighbor addr Neighbor ID State LSrxl DBsum LSreq Ifc
128.185.125.39 128.185.136.39 128 0 0 0 PPP/1
128.185.125.41 128.185.128.41 8 0 0 0 PPP/1
128.185.125.38 128.185.125.38 8 0 0 0 PPP/1
128.185.125.25 128.185.129.25 8 0 0 0 PPP/1
128.185.125.40 128.185.129.40 128 0 0 0 PPP/1
128.185.125.24 128.185.126.24 8 0 0 0 PPP/1
| Neighbor addr | Displays the neighbor address. |
| Neighbor ID | Displays the neighbor's OSPF router ID. |
| Neighbor State | Can be one of the following: 1 (Down), 2 (Attempt), 4 (Init), 8 (2-Way), 16 (ExStart), 32 (Exchange), 64 (Loading) or 128 (Full). |
| LSrxl | Displays the size of the current link state retransmission list for this neighbor. |
| DBsum | Displays the size of the database summary list waiting to be sent to the neighbor. |
| LSreq | Displays the number of more recent advertisements that are being requested from the neighbor. |
| Ifc | Displays the interface shared by the router and the neighbor. |
Example 2: neighbor 128.185.138.39
The meaning of most of the displayed fields is given in section 10 of the OSPF specification (RFC 1583) .
Neighbor IP address: 128.185.184.34
OSPF Router ID: 128.185.207.34
Neighbor State: 128
Physical interface: Eth/1
DR choice: 128.185.184.34
Backup choice: 128.185.184.11
DR Priority: 1
Nbr options: E,MC
Alternate TOS 0 cost: 5
DB summ qlen: 0 LS rxmt qlen: 0 LS req qlen: 0 Last hello: 7 No Hello Off # LS rxmits: 108 # Direct acks: 13 # Dup LS rcvd: 572 # Old LS rcvd: 2 # Dup acks rcv: 111 # Nbr losses: 29 # Adj. resets: 30
| Neighbor IP addr | Neighbor IP address. |
| OSPF router ID | Neighbor's OSPF router ID. |
| Neighbor State | Can be one of the following: 1 (Down), 2 (Attempt), 4 (Init), 8 (2-Way), 16 (ExStart), 32 (Exchange), 64 (Loading) or 128 (Full). |
| Physical interface | Displays physical interface type and number of the router and neighbor's common network. |
| DR choice, backup choice, DR priority | Indicate the values seen in the last hello received from the neighbor. |
| Nbr options | Indicates the optional OSPF capabilities supported by the neighbor. These capabilities are denoted by E (processes type 5 externals; when this is not set the area to which the common network belongs has been configured as a stub), T (can route based on TOS) and MC (can forward IP multicast datagrams). This field is valid only for those neighbors in state Exchng or greater. |
| DBsumm qlen | Indicates the number of advertisements waiting to be summarized in Database Description packets. It should be zero except when the neighbor is in state Exchange. |
| LS rxmt qlen | Indicates the number of advertisements that have been flooded to the neighbor, but not yet acknowledged. |
| LS req qlen | Indicates the number of advertisements that are being requested from the neighbor in state Loading. |
| Last hello | Indicates the number of seconds since a hello has been received from the neighbor. |
| # LS rxmits | Indicates the number of retransmissions that have occurred during flooding. |
| # direct acks | Indicates responses to duplicate link state advertisements. |
| # Dup LS rcvd | Indicates the number of duplicate retransmissions that have occurred during flooding. |
| # Old LS rcvd | Indicates the number of old advertisements received during flooding. |
| # Dup acks rcvd | Indicates the number of duplicate acknowledgments received. |
| # Nbr losses | Indicates the number of times the neighbor has changed to Down state. |
| # Adj. resets | Counts entries to state ExStart. |
See "Ping" for an explanation of the Ping command.
Use the OSPF reset command to dynamically modify the OSP routing configuration without restarting the router. For more information see "Dynamically Changing OSPF Configuration Parameters".
| Note: | During a restart, OSPF routes will be retained in the routing table to maintain IP forwarding. |
Syntax:
Example:
OSPF>interface Ifc Address Phys assoc. Area Type State Auth #nbrs #adjs 153.2.2.25 Eth/0 0.0.0.1 Brdcst 16 None 3 2 10.69.1.1 FR/0 0.0.0.0 P-2-MP 8 None 1 1 OSPF> *t 6 OSPF Config>delete interface 10.69.1.1 OSPF Config> *t 5 OSPF>reset ospf OSPF>interface Ifc Address Phys assoc. Area Type State Auth #nbrs #adjs 153.2.2.25 Eth/0 0.0.0.1 Brdcst 16 None 3 2
See "Traceroute" for an explanation of the Traceroute command.
Use the routers command to display all router routes that have been calculated by OSPF and are now present in the routing table. With the dump routing tables command, the Net field indicates that the destination is a network. The routers command covers all other destinations.
Syntax:
Example:
DType RType Destination AREA Cost Next hop(s)
ASBR SPF 128.185.142.9 0.0.0.1 1 128.185.142.9
Fadd SPF 128.185.142.98 0.0.0.1 1 0.0.0.0
Fadd SPF 128.185.142.7 0.0.0.1 1 0.0.0.0
Fadd SPF 128.185.142.48 0.0.0.1 1 0.0.0.0
Fadd SPF 128.185.142.111 0.0.0.1 1 0.0.0.0
Fadd SPF 128.185.142.38 0.0.0.1 1 0.0.0.0
Fadd SPF 128.185.142.11 0.0.0.1 1 0.0.0.0
BR SPF 128.185.142.9 0.0.0.2 1 128.185.142.9
BR SPF 128.185.142.9 0.0.0.2 2 128.185.184.114
Fadd SPF 128.185.142.47 0.0.0.2 1 0.0.0.0
| DType | Indicates destination type:
|
| RType | Indicates route type and how the route was derived:
|
| Destination | Destination router's OSPF ID. For Type D entries, one of the router's IP addresses is displayed (which corresponds to a router in another AS). |
| Area | Displays the AS area to which it belongs. |
| Cost | Displays the route cost. |
| Next hop | Address of the next router on the path toward the destination host. A number in parentheses at the end of the column indicates the number of equal-cost routes to the destination. |
Use the size command to display the number of LSAs currently in the link state database, categorized by type.
Syntax:
Example:
# Router-LSAs: 6
# Network-LSAs: 2
# Summary-LSAs: 45
# Summary Router-LSAs: 6
# AS External-LSAs: 2
# Group-membership-LSAs: 11
# Intra-area routes: 11
# Inter-area routes: 15
# Type 1 external routes: 0
# Type 2 external routes: 2
Use the statistics command to display statistics generated by the OSPF routing protocol. The statistics indicate how well the implementation is performing, including its memory and network utilization. Many of the fields displayed are confirmation of the OSPF configuration.
Syntax:
Example:
OSPF>statistics
OSPF Router ID: 1.1.1.1
External comparison: Type 2
RFC 1583 compatibility: Yes
Demand circuit support: Yes
AS boundary capability: No
Import external routes: None
Orig. default route: No (0,0.0.0.0)
Default route cost: (1, Type 2)
Default forward. addr: 0.0.0.0
Attached areas: 1 Estimated # external routes: 1000
Estimated # OSPF routers: 50 Estimated heap usage: 148000
OSPF packets rcvd: 63 OSPF packets rcvd w/ errs: 1
Transit nodes allocated: 21 Transit nodes freed: 17
LS adv. allocated: 83 LS adv. freed: 61
Queue headers alloc: 64 Queue headers avail: 64
Maximum LSA size: 2048
# Dijkstra runs: 7 Incremental summ. updates: 2
Incremental VL updates: 0 Buffer alloc failures: 0
Multicast pkts sent: 31 Unicast pkts sent: 19
LS adv. aged out: 9 LS adv. flushed: 11
Ptrs To Invalid LS adv: 0 Incremental ext. updates: 14
LSA Max Random Initial Age: 1770 LSA MINARRIVAL rejects: 1
External LSA database:
Current state: Normal
Number of LSAs: 10 Number of overflows: 0
| OSPF Router ID | Displays the router's OSPF ID. |
| External comparison | Displays the external route type used by the router when importing external routes. |
| RFC 1583 compatibility | Indicates whether or not OSPF AS external route computation will be compatible with RFC 1583. |
| AS boundary capability | Displays whether external routes will be imported. |
| Import external routes | Displays which external routes will be imported. |
| Orig default route | Displays whether the router will advertise an OSPF default route. If the value is "Yes" and a nonzero number is displayed in parentheses, then a default route will be advertised only when a route to the network exists. |
| Default route cost | Displays the cost and type of the default route (if advertised). |
| Default forward addr | Displays the forwarding address specified in the default route (if advertised). |
| Attached areas | Indicates the number of areas that the router has active interfaces to. |
| Estimated heap usage | Rough indication of the size of the OSPF link state database (in bytes). |
| Transit nodes | Allocated to store router links and network links advertisements. |
| LS adv. | Allocated to store summary link and AS external link advertisements. |
| Queue headers | Form lists of link state advertisements. These lists are used in the flooding and database exchange processes; if the number of queue headers allocated is not equal to the number freed, database synchronization with some neighbor is in progress. |
| # Dijkstra runs | Indicates how many times the OSPF routing table has been calculated from scratch. |
| Maximum LSA size | The maximum size LSA that can be originated by this router. This is the minimum of the value configured through OSPF configuration and the maximum packet size computed or configured through general configuration. |
| Incremental summ updates, incremental VL updates | Indicate that new summary link advertisements have caused the routing table to be partially rebuilt. |
| Buffer alloc failures. | Indicate buffer allocation failures. The OSPF system will recover from temporary lack of packet buffers. |
| Multicast pkts sent | Covers OSPF hello packets and packets sent during the flooding procedure. |
| Unicast pkts sent | Covers OSPF packet retransmissions and the Database Exchange procedure. |
| LS adv. aged out | Counts the number of advertisements that have hit 60 minutes. Link state advertisements are aged out after 60 minutes. Usually they will be refreshed before this time. |
| LS adv. flushed | Indicates number of advertisements removed (and not replaced) from the link state database. |
| Ptrs to Invalid LS adv | Displays number of advertisements in the database which were malformed and could not be interpreted. |
| Incremental ext. updates. | Displays number of changes to external destinations that are incrementally installed in the routing table. |
| External LSA database: | Provides information about the LSA database:
|
Use the weight command to change the cost of one of the routers OSPF interfaces. This new cost is immediately flooded throughout the OSPF routing domain, causing routes to be updated accordingly.
The cost of the interface will revert to its configured cost whenever the router is restarted or reloaded. To make the cost change permanent, you must reconfigure the appropriate OSPF interface after invoking the weight command. This command will cause a new router links advertisement to be originated, unless the cost of the interface does not change.
Syntax:
Example: weight 128.185.124.22 2