Open Shortest Path First

Introduction

The Open Shortest Path First (OSPF) protocol is a link state routing protocol. Its IPv4 networking version is specified as OSPFv2 and the IPv6 version is defined as OSPFv3. Both versions can be configured using FRR and their full documentation is available for both OSPFv2 and OSPFv3 versions, respectively.

This section provides an overview on how to configure both versions on BISDN Linux.

OSPFv2 configuration

OSPF must first be enabled in /etc/frr/daemons file. The relevant file for this test case must then be configured, /etc/frr/frr.conf.

zebra=yes
bgpd=no
ospfd=yes
...
vtysh_enable=yes
zebra_options="  -A 127.0.0.1 -s 90000000"

The zebra configuration will set IP addresses on the interfaces with the configuration snippet. It is not required that the same tools are used, just that the system is correctly configured for the connectivity tests.

Regarding OSPFv2, the configuration here must specify the point-to-point parameter in the interface specific section, to enable the protocol on the port53 link between the two Basebox routers. The redistribute connected command is a “smart” flag by FRR, that will redistribute every network configured on the router.

interface port1
  no shutdown
  ip address 10.1.1.1/24

interface port53
  ip ospf mtu-ignore
  ip ospf network point-to-point
!
router ospf
      ospf router-id 
      redistribute connected
      network 10.0.254.0/24 area 0.0.0.1
exit

OSPF expected result and debugging

Analogous to the previous protocols debugging commands, we can run the following commands to verify the configuration.

ip route

(vtysh) show ip ospf sum

(vtysh) show ip ospf neighbors

OSPFv3

OSPFv3 must first be enabled in /etc/frr/daemons file. The relevant file for this test case must then be configured, /etc/frr/frr.conf.

zebra=yes
bgpd=no
ospf6d=yes
...
vtysh_enable=yes
zebra_options="  -A 127.0.0.1 -s 90000000"
...

The zebra configuration will configure IP addresses on the interfaces, with the configuration snippet. The following configurations allow setting up the Router neighboring discover packets and IP address auto-configuration.

Regarding OSPFv3, the configuration here must specify the point-to-point parameter in the interface specific section, to enable the protocol on the port53 link between the two Basebox routers. The redistribute connected command is a “smart” flag by FRR, that will redistribute every network configured on the router.

interface port1
  no shutdown
  no ipv6 nd suppress-ra
  ipv6 nd prefix 2001:db8:1::/64

interface port53
  ipv6 ospf6 mtu-ignore
  ipv6 ospf6 network point-to-point
  ipv6 ospf6 area 10.10.10.10
!
router ospf6
      ospf6 router-id 
      redistribute connected
exit

OSPFv3 expected result and debugging

Analogous to the previous protocols debugging commands, we can run the following commands to verify the configuration.

(vtysh) show ip ospf sum

(vtysh) show ip ospf neighbors

ip route