AN-002 Implementing dynamic routing with quagga

Warning

Support for Quagga will be deprecated in SD-WAN 6.9. If Quagga is enabled on nodes running 6.9, dynamic routing will not work. Please see Configuring dynamic routing in bonding for instructions on how to configure dynamic routing protocols directly on bonders and aggregators.

Tip

As of 6.5, dynamic routing protocols can be configured directly on bonders and aggregators in their networking configuration. This method is significantly more integerated into bonding and adds support for more protocols.

Warning

If you ever restart the quagga service the bonding service MUST be restarted otherwise it is possible you will be missing route entries and as a result bonding will not properly function.

Dynamic routing is an integral part of modern networking and is widely used across many organizations and applications. In the case of bonding, it is a common scenario where you want to communicate to an external host from a node (or vice-versa) and dynamic routing makes for a powerful solution.

All of the options listed assume that any necessary setup on the other side of a protocol have already been handled. For example, if OSPF does not have the expected neighbor their won’t be anything to route to. These implementations are also minimal for the sake of simplicity. To get the most out of dynamic routing for your use case be sure to read the linked documentation.

Quagga is an open-source routing suite that allows for the creation of routing protocols as daemons. These daemons communicate with the Zebra daemon, which acts as the layer between the user and the kernel. For our purposes Quagga supports OSPF and BGP in both IPv4 and IPV6.

SD-WAN integrates with the Quagga routing service for publishing routes into OSPF or BGP networks. This document describes how to configure Quagga. Since each partner’s network is unique, Quagga must be manually configured on each aggregator using the unique settings for each network.

Further reading

More information about Quagga is available at:

Configuring Quagga via vtysh

Quagga is configured though a Cisco-like console called vtysh. Like Cisco, vtysh has three modes:

  1. View mode, similar to user exec mode in Cisco, used for read-only access to Quagga

  2. Enable mode, similar to privileged exec mode in Cisco, used for read-write access to Quagga

  3. Configuration mode, similar to global configuration mode in Cisco, used to modify Quagga’s running configuration

The initial vtysh mode is enable mode.

To start the console, log in as root and run vtysh. You will be presented with the standard login banner and prompt:

root@host:~# vtysh
Hello, this is Quagga (version 0.99.22.4).
Copyright 1996-2005 Kunihiro Ishiguro, et al.
host#

To see the list of available commands, type ? at the prompt. To show valid arguments for a command, type the command name and then type ?.

vtysh understands abbreviated commands. For example, configure terminal can be abbreviated as conf t.

Changing modes

The following commands change modes in vtysh:

Current mode

New mode

Command

Shortcut

View

Enable

enable

en

Enable

View

disable

dis

Enable

Configuration

configure terminal

conf t

Configuration

Enable

end

Common enable mode commands

Action

Command

Shortcut

Show complete configuration

show running-config

show run

Enter configuration mode

configure terminal

conf t

Save the updated configuration to disk

copy running-config startup-config

copy run start

Show routing table

show ip route

sh ip ro

Show OSPF neighbors

show ip ospf neighbor

sh ip os ne

Show BGP neighbors

show ip bgp neighbors

sh ip bgp ne

Common configure mode commands

In configure mode, prepend no to a command to reset that configuration to its default or to remove the configuration. For example, if OSPF was enabled, you could disabled it by running no router ospf.

Action

Command

Shortcut

Exit current configuration mode and go down to previous mode

exit

ex

Exit configuration mode and return to enable mode

end

Configure OSPF routing

router ospf

Configure BGP routing

router bgp

Configure interface

interface <interface name>

int <interface name>

OSPF configuration

To use OSPF in Quagga, first enable the protocol. Run the following commands from a Linux shell (not vtysh):

sed -i 's/ospfd=no/ospfd=yes/' /etc/quagga/daemons
touch /etc/quagga/ospfd.conf
chmod 640 /etc/quagga/ospfd.conf
chown quagga:quagga /etc/quagga/ospfd.conf
service quagga restart

Then run vtysh.

Enter configuration mode:

configure terminal

You are now in configuration mode, indicated by the (config)# prompt.

To enable and configure OSPF, run:

router ospf

You are now in OSPF configuration mode, indicated by the (config-router)# prompt.

Run commands to configure OSPF. At the minimum, you must provide a router ID (typically the node’s IPv4 address is used), redistribute static routes, and specify a network and area (if unsure, the area can be 0.0.0.0):

ospf router-id <router ID or IPv4>
redistribute static
network <network/subnet> area <area, or just 0.0.0.0>

To see all the available OSPF settings, type ? at the prompt or review the Quagga documentation.

A number of OSPF-related settings are available under the interface configuration mode. To enter this mode, run interface <interface name>. For example, to configure OSPF settings for the network on eth0, run interface eth0. The prompt will change to (config-if)#, indicating you are in interface configuration mode. Type ospf ? to list the available OSPF configuration options.

When OSPF is configured, type end to leave configuration mode. Verify that neighbor routers have been found by running show ip ospf neighbor and that OSPF routes are being received by running show ip ospf route. To save the configuration to disk, run copy run start.

Note

For a node to discover neighbors via OSPF, the OSPF protocol must be accepted by the firewall. If a node does not have an iptables rule to accept neighbor traffic using protocol 89, it will not be able to discover neighbors via OSPF.

OSPF6 configuration

To use OSPF6 in Quagga, first enable the protocol. Run the following commands from a Linux shell (not vtysh):

sed -i 's/ospf6d=no/ospf6d=yes/' /etc/quagga/daemons
touch /etc/quagga/ospf6d.conf
chmod 640 /etc/quagga/ospf6d.conf
chown quagga:quagga /etc/quagga/ospf6d.conf
service quagga restart

Note

These commands are different than as they appear for OSPF in the previous section. You must run each set of commands to use the corresponding protocol.

Then run vtysh.

Enter configuration mode:

configure terminal

You are now in configuration mode, indicated by the (config)# prompt.

To enable and configure OSPF6, run:

router ospf6

You are now in OSPF6 configuration mode, indicated by the (config-ospf6)# prompt.

Run commands to configure OSPF6. At the minimum, you must provide a router ID (like for OSPF, typically the node’s IPv4 address is used), redistribute static routes, an area with a range of IPv6 addresses, and an interface belonging to that area.

router-id <router ID or IPv4>
redistribute static
area <area, or just 0.0.0.0> range <IPv6 network/subnet>
interface <ifname> area <area, or just 0.0.0.0>

To see all the available OSPF6 settings, type ? at the prompt or review the Quagga documentation.

Like for OSPF, many OSPF6 settings can be configured on an interface level from the interface configuration terminal.

When OSPF6 is configured, type end to leave configuration mode. Verify that neighbor routers have been found by running show ipv6 ospf6 neighbor and that OSPF6 routes are being received by running show ipv6 ospf6 route. To save the configuration to disk, run copy run start.

Note

For a node to discover neighbors via OSPF6, the OSPF protocol must be accepted by the firewall. If a node does not have an ip6tables rule to accept neighbor traffic using protocol 89, it will not be able to discover neighbors via OSPF6.

BGP configuration

To use BGP in Quagga, first enable the protocol. Run the following commands from a Linux shell (not vtysh):

sed -i 's/bgpd=no/bgpd=yes/' /etc/quagga/daemons
touch /etc/quagga/bgpd.conf
chmod 640 /etc/quagga/bgpd.conf
chown quagga:quagga /etc/quagga/bgpd.conf
service quagga restart

Then run vtysh.

Enter configuration mode:

configure terminal

You are now in configuration mode, indicated by the (config)# prompt.

To enable and configure BGP, run:

router bgp <your AS number>

You are now in BGP configuration mode, indicated by the (config-router)# prompt.

Run commands to configure BGP. At the minimum, you must provide a router ID (for example, the IP address of the aggregator), redistribute static routes, and specify a neighbor:

bgp router-id <router ID>
redistribute static
neighbor <neighbor IP> remote-as <neighbor's AS number>

To export IPv6 routes as well, you will also need to set the following under the bgp configuration:

address-family ipv6
redistribute static
neighbor <neighbor IP> activate
exit-address-family

To see all the available BGP settings, type ? at the prompt or review the Quagga documentation.

When BGP is configured, type end to leave configuration mode. Verify that neighbor routers have been found by running show ip bgp neighbors. To save the configuration to disk, run copy run start.