Enables OSPF ospf Not-So-Stubby Area (OSPF NSSA) area where RFC 3101 is disabled, RFC 1587 is Blocks the flooding of OSPF LSA packets to the interface. rfc1587. Access to most tools on the Cisco Support and routes from one routing domain to another routing domain. The OSPF metric is calculated as the ref-bw value divided by the bandwidth value, with the ref-bw value equal to 108 by default, and the bandwidth value determined by the bandwidth interface configuration command. Therefore, if you do configure any of these parameters, ensure that the configurations for all routers on your network have compatible values. area-id Unless noted otherwise, subsequent releases of that software release train also support that feature. ip OSPF will originate the default route (network 0.0.0.0) with a Type 2 metric of 5 if 172.16.0.0 is in the routing table. (config-router)#. Forces the ASBR to generate a default route into the OSPF routing domain. The command includes a wild card mask that specifies the range of IP addresses. OSPF automatically prefers a loopback interface over any other kind, and it chooses the highest IP address among all loopback interfaces. OSPF Configuration Commands Step by Step Configure OSPF in Router 1 Router# Router#conf t Router (config)#router ospf 10 Router (config-router)#network 1.0.0.0 .255.255.255 area 1 Router (config-router)#network 10.0.0.0 .255.255.255 area 1 Router (config-router)#^Z (Use Ctrl + Z to save settings) Configure OSPF in Router 2 Router# Router#conf t There is sufficient host address space for two host endpoints on a point-to-point serial link. To quickly configure an OSPFv2 interface on a point-to-multipoint network, copy the following commands and paste them into the CLI. Cisco supports RFC 1253, [not-advertise][tag This tutorial is the last part of this article. The virtual link must be configured in both routers. seconds] [dead-interval adjacencies belonging to an OSPF interface. wildcard-mask terminal, 3. summary-address md5 Command Reference, Protocol-independent features that work with OSPF, Configuring IP Routing Protocol-Independent Features module in Same config should be made for R2# R3# R4# R5# too.. seconds, 10. spf-max-wait, 1. ip-address The table below describes the The router refreshes LSAs that it generated; it ages the LSAs that it received from other routers. By default, OSPF floods new LSAs over all interfaces in the same area, except the interface on which the LSA arrives. show At the interdomain level, OSPF can import routes learned via Exterior Gateway Protocol (EGP) and Border Gateway Protocol (BGP). 2 After configuring first step, which router is DR and which router is BDR in Area 0 ? You can configure your network as either a broadcast or an NBMA network. It is used to create or modify an . If RFC 3101 is disabled, the forced NSSA LSA translator nssa However, an ASBR does not, by default, generate a defaultroute into the OSPF routing domain. show ospfv3 OSPF areas are explained in second part this article. Every router within a stub area or NSSA must have this feature loaded in order to take advantage of the on-demand circuit functionality. During flooding, several neighbors sent updates to a single router at the same time. If a loopback interface is configured with an IP address, the Cisco IOS software will use this IP address as its router ID, even if other interfaces have larger IP addresses. ip Assume that a match is determined for Ethernet interface 1. area command in this example is a special case. Displays a list of OSPF LSAs waiting to be flooded over an interface. We will use same commands to assign IP addresses on interfaces of remaining routers. 1194NorthMathildaAvenue Sunnyvale,California94089 USA 408-745-2000 www.juniper.net ThisproductincludestheEnvoySNMPEngine . Prior to Cisco IOS Release 12.0, some customers were using point-to-multipoint on nonbroadcast media (such as classic IP over ATM), so their routers could not dynamically discover their neighbors. 2. In the second step, we provide the required details to the EIGRP. nssa The following table provides release information about the feature or features described in this module. Therefore, the router delays the LSA refresh function for an interval of time instead of performing it when the individual timers are reached. To enable the OSPF routing process, enter the following command in global configuration mode. Hello timer must be match on both routers in order become neighbors. Priority value is configured under the related interface. Router#configure terminal Command is used to enter in global configuration mode. The following example outlines a configuration for several routers within a single OSPF autonomous system. 2 network address wildcard-mask area area-id Define an interface on which OSPF runs and define the area ID for that interface. support. ignore keyword in the type-value] Sets the Now router will look for 172.168.1.x and 172.168.2.x network. X.25 and Frame Relay provide an optional broadcast capability that can be configured in the map to allow OSPF to run as a broadcast network. configure Because loopback interfaces never go down, greater stability in the routing table is achieved. Interface mode can be accessed from global configuration mode. 5Configure summarization on ASBR routers. 3. OSPF is an Interior Gateway Protocol (IGP) developed by the OSPF working group of the Internet Engineering Task Force (IETF). Above commands will ask router to match /24 bits of address instead of default /16 bits. For a complete description of the OSPF commands Step Command Purpose 1 router ospf process-id Enable OSPF routing, which places you in router configuration mode. Displays the internal OSPF routing table entries to the ABR and ASBR. (compatible with RFC 1587). ip ospf OSPF uses three different administrative distances: intra-area, interarea, and external. huge map-name]. nssa This part explains these states with DR BDR selection process in detail with examples. as a forced NSSA LSA translator. Process ID is used to differentiate between them. If no loopback interfaces are present, the highest IP address in the router is chosen. In those tutorials wildcard masks are explained in detail with examples. By default, OSPF classifies different media into the following three types of networks: Broadcast networks (Ethernet, Token Ring, and FDDI), Nonbroadcast multiaccess (NBMA) networks (Switched Multimegabit Data Service [SMDS], Frame Relay, and X.25), Point-to-point networks (High-Level Data Link Control [HDLC] and PPP). may not support all the features documented in this module. Any IP interface on the switch that has an IP address within the range will run OSPF. router ospf Choose the router ID for each router. You can force an ASBR to generate a default route into an OSPF routing domain. In this article we will see how to configure OSPF step by step. Finding Feature Information Prerequisites for IPv6 Routing: OSPFv3 Restrictions for IPv6 Routing: OSPFv3 Information About IPv6 Routing: OSPFv3 How to Configure Load Balancing in OSPFv3 We can use show controllers interface command from privilege mode to check the cables end. Task Command Step 1 Enable OSPF routing, which places you in router conguration mode. set interfaces at-0/1/0 unit 0 family inet address 192.0.2.2 set protocols ospf area 0.0.0.1 interface at-0/1/0 neighbor 192.0.2.1. You may also like: Configuring a single-area OSPF for a network topology of three Cisco routers and five networks. Router(config-if)#ip ospf dead-interval 60, Set dead interval timer to 60 seconds. In this article we made an OSPF configuration example for a better understanding of OSPF protocol. www.cisco.com/go/cfn. Displays OSPF-related interface information. You can specify the following neighbor parameters, as required: On point-to-multipoint, nonbroadcast networks, use the Router id value should be configured first when we configure OSPF . configure ip configure With the following configuration, OSPF external routes with tags 1, 2, 3, and 5 are redistributed into RIP with metrics of 1, 1, 5, and 5, respectively. summary-prefix (OSPFv3) command. arguments must match values specified for other neighbors on a network segment. [autonomous-system-number] within the same area must agree that the area is NSSA; otherwise, the devices Both devices are able to see each other via the hello packet generated for the receiving interface. [process-id] You can use the optional 1. compatible example, the output for the Sample OSPF Autonomous System Network Map, Figure 6. frame-relay OSPF external routes are advertised inside as E1 or E2 type routes. Learn OSPF configuration commands, OSPF show commands, OSPF network configuration (Process ID, Network ID, Wild card mask and Area number) and OSPF routing in detail. ip 3. seconds] [retransmit-interval seconds, 6. adjacency flood-list ospf Router(config)#interface serial 0/0/0 Command is used to enter in interface mode. OSPF Configuration Verification If you have access to the privileged mode of OSPF routers, you can use 'show running-config' to verify the configuration. Differentiates Point-to-Multipoint with Broadcast, Example: OSPF network in the example, Routing Information Protocol (RIP) subnets are redistributed into the Routing between two routers that are not directly connected will go through the router that has VCs to both routers. cost b. number of seconds between link-state advertisement (LSA) retransmissions for 3 Define Router 1 DR in Area 0 and Router 2 and Router 3 is not a BDR .rea 0da R1i DR yapn. ospf Note that for Router C, Area 1 is assigned to E3 and area 0 is assigned to S0. You cannot tell OSPF to use any particular interface. 1 Configure OSPF for the network above. process-id argument identifies the OSPF process. 0.0.0.255 area 9! interfaces on which OSPF runs and the area ID for those interfaces. network An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored. The table below describes the Exits router configuration mode and returns to privileged EXEC mode. Assign link-state metrics and other OSPF interface configuration options. In the figure below, Router 1 uses data-link connection identifier (DLCI) 201 to communicate with Router 2, DLCI 202 to communicate with Router 4, and DLCI 203 to communicate with Router 3. R6 (config)#router ospf 1. Exits router R6>en. Configuration_of_Routers.doc Introduction to Routing and Packet Forwarding Lab: Basic Router Configuration 1992-2007 Cisco of Router R2. Dead interval timer must be match on both routers in order to become neighbor, Display all routers learned through OSPF from routing table, Display information about all OSPF active interfaces, Router#show ip ospf interface serial 0/0/0, Display OSPF information about serial 0/0/0 interface, Clear particular route from routing table. Router(config)# router rip Step 2: Enter classful network addresses Once you are in routing configuration mode, enter the classful network address for each directly