Configuring OSPF Static Neighbors

In this lab you will learn how to configure Open Shortest Path First (OSPF) static neighbors to induce neighbor relationships on a non-broadcast network such as frame relay.

Real World Application & Core Knowledge

In lab 9-1 when you configured OSPF initially you had to change the frame relay hub and spoke network type to broadcast to ensure the neighbor relationships formed. However the default network type for OSPF on a serial interface with frame relay encapsulation is non-broadcast. With this in mind you must configure static neighbors to ensure OSPF can form a neighbor relationship, this is due to frame relay trading multicast as pseudo-broadcast and if a frame relay PVC (Permanent Virtual Circuit) is not broadcast capable then multicast would not traverse the PVC.

In this lab you will revert the routers serial interfaces in the hub-and-spoke topology back to its default, non-broadcast and configure a static neighbor statement on R1. The static neighbor statement only needs to be configured on the hub however its best to configure it on both hub and spokes to ensure initialization of neighbor negotiation.

You can manually specify the network type as non-broadcast on the interface of you can negate the current OSPF network type on the interfaces thus reverting it back to its default; either way will suffice for this lab.

Familiarize yourself with the following new command(s);

no ip ospf network – Executed in interface configuration mode to revert the OSPF network type back to its default for that specified interface.

ip ospf network non-broadcast – Executed in interface configuration mode to configure the specified interface opsf network type to non-broadcast; this mode requires static neighbor statements and will form a DR/BDR relationship.

The following logical topology shown below is used in labs found through out Section 9 – Configuring OSPF;

Lab Prerequisites

• If you completed lab 9-3 you can start where you’ve left off or you can load the Free CCNA Workbook GNS3 topology; start and establish a console session with R1, R2, R3, R4, R5 and SW1 then load their initial configurations included below by copying the config from the textbox and pasting it into the routers console.

Initial Configurations

!################################################## !#  Free CCNA Workbook Lab 9-4 R1 Initial Config  # !################################################## ! enable configure terminal ! hostname R1 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.10.1 255.255.255.0 ! interface Serial1/0  description ### PHYSICAL FRAME RELAY INTERFACE ###  ip address 10.1.245.1 255.255.255.248  ip ospf network point-to-multipoint  encapsulation frame-relay  serial restart-delay 0  frame-relay map ip 10.1.245.5 125 broadcast  frame-relay map ip 10.1.245.4 124 broadcast  frame-relay map ip 10.1.245.2 122 broadcast  no frame-relay inverse-arp  no shut  exit ! router ospf 1  log-adjacency-changes  network 10.1.245.1 0.0.0.0 area 0 ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-4 R2 Initial Config  # !################################################## ! enable configure terminal ! hostname R2 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.20.1 255.255.255.0 ! interface Serial1/0  description ### PHYSICAL FRAME RELAY INTERFACE ###  ip address 10.1.245.2 255.255.255.248  encapsulation frame-relay  ip ospf network point-to-multipoint  ip ospf priority 0  serial restart-delay 0  no frame-relay inverse-arp  frame map ip 10.1.245.1 221 broadcast  frame map ip 10.1.245.4 221  frame map ip 10.1.245.5 221  no shut ! interface Serial1/2  ### POINT-TO-POINT LINK TO R3 ###  ip address 10.1.23.1 255.255.255.252  encapsulation ppp  serial restart-delay 0  no shut  exit ! router ospf 1  log-adjacency-changes  network 10.1.245.2 0.0.0.0 area 0 ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-3 R3 Initial Config  # !################################################## ! enable configure terminal ! hostname R3 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.30.1 255.255.255.0 ! interface Serial1/1  description ### POINT-TO-POINT LINK TO R2 ###  ip address 10.1.23.2 255.255.255.252  encapsulation ppp  no shut  exit ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-4 R4 Initial Config  # !################################################## ! enable configure terminal ! hostname R4 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.40.1 255.255.255.0 ! interface FastEthernet0/0  description ### REAL NETWORK ###  ip address 10.45.1.1 255.255.255.0  no shut ! interface Serial1/0  description ### PHYSICAL FRAME RELAY INTERFACE ###  ip address 10.1.245.4 255.255.255.248  encapsulation frame-relay  ip ospf network point-to-multipoint  ip ospf priority 0  serial restart-delay 0  no frame-relay inverse-arp  frame map ip 10.1.245.1 421 broadcast  frame map ip 10.1.245.2 421  frame map ip 10.1.245.5 421  no shut ! interface Serial1/1  description ### POINT-TO-POINT LINK TO R5 ###  ip address 10.1.45.1 255.255.255.252  encapsulation ppp  serial restart-delay 0  no shut  exit ! router ospf 1  log-adjacency-changes  network 10.1.245.4 0.0.0.0 area 0 ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-4 R5 Initial Config  # !################################################## ! enable configure terminal ! hostname R5 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.50.1 255.255.255.0 ! interface FastEthernet0/0  description ### REAL NETWORK ###  ip address 10.45.1.2 255.255.255.0  no shut ! interface Serial1/0  description ### PHYSICAL FRAME RELAY INTERFACE ###  ip address 10.1.245.5 255.255.255.248  encapsulation frame-relay  ip ospf network point-to-multipoint  ip ospf priority 0  serial restart-delay 0  no frame-relay inverse-arp  frame map ip 10.1.245.1 521 broadcast  frame map ip 10.1.245.2 521  frame map ip 10.1.245.4 521  no shut ! interface Serial1/1  description ### POINT-TO-POINT LINK TO R4 ###  ip address 10.1.45.2 255.255.255.252  encapsulation ppp  serial restart-delay 0  no shut  exit ! router ospf 1  log-adjacency-changes  network 10.1.245.5 0.0.0.0 area 0 ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-4 SW1 Initial Config # !################################################## ! enable configure terminal ! hostname SW1 no ip domain-lookup ! line con 0  logging sync  no exec-timeout ! end

Lab Objectives

• Revert the OSPF interface type back its default on R1, R2, R4 and R5′s frame relay hub and spoke interfaces.
• Configure static neighbor statements on R1 pointing to R2, R4 and R5.
• Verify that the neighbor relationships form using the show ip ospf neighbor command.

Lab Instruction

Objective 1. – Revert the OSPF interface type back its default on R1, R2, R4 and R5′s frame relay hub and spoke interfaces.

R1>enable R1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R1(config)#interface Serial1/0 R1(config-if)#no ip ospf network R1(config-if)#end R1# %OSPF-5-ADJCHG: Process 1, Nbr 10.55.20.1 on Serial1/0 from FULL to DOWN, Neighbor Down: Interface down or detached %OSPF-5-ADJCHG: Process 1, Nbr 10.55.40.1 on Serial1/0 from FULL to DOWN, Neighbor Down: Interface down or detached %OSPF-5-ADJCHG: Process 1, Nbr 10.55.50.1 on Serial1/0 from FULL to DOWN, Neighbor Down: Interface down or detached R1# *Jul 8 20:19:16.767: %SYS-5-CONFIG_I: Configured from console by console R1#

R2>enable R2#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R2(config)#interface Serial1/0 R2(config-if)#no ip ospf network R2(config-if)#end R2#

R4>enable R4#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R4(config)#interface Serial1/0 R4(config-if)#no ip ospf network R4(config-if)#end R4#

R5>enable R5#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R5(config)#interface Serial1/0 R5(config-if)#no ip ospf network R5(config-if)#end R5#

Objective 2. – Configure static neighbor statements on R1 pointing to R2, R4 and R5.

R1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R1(config)#router ospf 1 R1(config-router)#neighbor 10.1.245.2 R1(config-router)#neighbor 10.1.245.4 R1(config-router)#neighbor 10.1.245.5 R1(config-router)#end R1# %OSPF-5-ADJCHG: Process 1, Nbr 10.55.20.1 on Serial1/0 from LOADING to FULL, Loading Done %OSPF-5-ADJCHG: Process 1, Nbr 10.55.40.1 on Serial1/0 from LOADING to FULL, Loading Done %OSPF-5-ADJCHG: Process 1, Nbr 10.55.50.1 on Serial1/0 from LOADING to FULL, Loading Done R1#

Objective 3. – Verify that the neighbor relationships form using the show ip ospf neighbor command.

R1#show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
10.55.20.1        0   FULL/DROTHER    00:01:51    10.1.245.2      Serial1/0
10.55.40.1        0   FULL/DROTHER    00:01:35    10.1.245.4      Serial1/0
10.55.50.1        0   FULL/DROTHER    00:01:45    10.1.245.5      Serial1/0
R1#