An actual recreation of this problem is described in this section.
Router 6 and Router 7 in the above topology are connected via Frame Relay and Router 6 has been configured with 5 static routes redistributed into OSPF. The serial interface on Router 6 has the default MTU of 1500, while the serial interface on Router 7 has an MTU of 1450. Each router configuration is shown in the table below (only necessary configuration information is shown):
|Router 6 Configuration||Router 7 Configuration|
interface Serial2 !--- MTU sets to it's default value of 1500. no ip address no ip directed-broadcast encapsulation frame-relay no ip mroute-cache frame-relay lmi-type ansi ! interface Serial2.7 point-to-point ip address 220.127.116.11 255.255.255.0 no ip directed-broadcast frame-relay interface-dlci 101 ! router ospf 7 redistribute static subnets network 18.104.22.168 0.0.0.255 area 0 ip route 22.214.171.124 255.255.255.0 Null0 ip route 126.96.36.199 255.255.255.0 Null0 ip route 188.8.131.52 255.255.255.0 Null0 ip route 184.108.40.206 255.255.255.0 Null0 ip route 220.127.116.11 255.255.255.0 Null0
! interface Serial0 mtu 1450 no ip address no ip directed-broadcast encapsulation frame-relay frame-relay lmi-type ANSI ! interface Serial0.6 point-to-point ip address 18.104.22.168 255.255.255.0 no ip directed-broadcast frame-relay interface-dlci 110! ! router ospf 7 network 22.214.171.124 0.0.0.255 area 0
The show ip ospf neighbor command output for each router is: