Turn Your CentOS into an OSPF Router with Quagga

QuaggaQuagga is open-source routing software that turns Linux into a router supporting RIP, OSPF, BGP, and IS-IS. It supports IPv4/IPv6 with route/prefix filtering.

In this tutorial, we’ll connect two branch networks (192.168.1.0/24 and 172.17.1.0/24) via a dedicated link.

CentOS。Settings“site-A-RTR”“site-B-RTR'。IPAddress。

• Site-A: 192.168.1.0/24
• Site-B: 172.16.1.0/24
• Peer network between two Linux routers: 10.10.10.0/30

Quagga。，。

1. Zebra: ，。
2. Ospfd: IPv4 OSPF 。

Installing Quagga on CentOS

We install Quagga using yum.

1. # yum install quagga

On CentOS 7, SELinux blocks quagga from writing config files. We need to disable this policy.SELinux（），“zebrawriteconfig”。CentOS 6。

1. # setsebool -P zebra_write_config 1

Without this change, you’ll see errors when saving Quagga config.

1. Can't open configuration file /etc/quagga/zebra.conf.OS1Uu5.

After installing, configure peer IPs and OSPF settings. Quagga includes vtysh, similar to Cisco/Juniper CLI.

Step 1: Configure Zebra

Create Zebra config file and enable the Zebra daemon.

1. # cp /usr/share/doc/quagga-XXXXX/zebra.conf.sample /etc/quagga/zebra.conf
2. # service zebra start
3. # chkconfig zebra on

Start vtysh CLI:

1. # vtysh

Configure Zebra log file. Enter vtysh global config mode:

1. site–A–RTR# configure terminal

Specify log file location, then exit:

1. site–A–RTR(config)# log file /var/log/quagga/quagga.log
2. site–A–RTR(config)# exit

Permanently save config:

1. site–A–RTR# write

Identify available interfaces and configure IPs.

1. site–A–RTR# show interface

1. Interface eth0 is up, line protocol detection is disabled
2. . . . . .
3. Interface eth1 is up, line protocol detection is disabled
4. . . . . .

Configure eth0:

1. site–A–RTR# configure terminal
2. site–A–RTR(config)# interface eth0
3. site–A–RTR(config–if)# ip address 10.10.10.1/30
4. site–A–RTR(config–if)# description to–site–B
5. site–A–RTR(config–if)# no shutdown

Configure eth1:

1. site–A–RTR(config)# interface eth1
2. site–A–RTR(config–if)# ip address 192.168.1.1/24
3. site–A–RTR(config–if)# description to–site–A–LAN
4. site–A–RTR(config–if)# no shutdown

Verify config:

1. site–A–RTR(config–if)# do show interface

1. Interface eth0 is up, line protocol detection is disabled
2. . . . . .
3. inet 10.10.10.1/30 broadcast 10.10.10.3
4. . . . . .
5. Interface eth1 is up, line protocol detection is disabled
6. . . . . .
7. inet 192.168.1.1/24 broadcast 192.168.1.255
8. . . . . .

1. site–A–RTR(config–if)# do show interface description

1. Interface Status Protocol Description
2. eth0 up unknown to–site–B
3. eth1 up unknown to–site–A–LAN

Permanently save config:

1. site–A–RTR(config–if)# do write

Repeat IP configuration on site-B.

If successful, you can ping the peer IP 10.10.10.2 from site-A.

Note: Changes in vtysh take effect immediately once Zebra is running. No restart needed.