6.7. Using RIP Dynamic Routing on Debian

Problem

Your networks aren't all that complex, but you don't want to hassle with manually configuring routes. Isn't this the kind of work that computers should be doing, the repetitive boring stuff? Your routers are Debian-based.

Solution

Indeed, this is the sort of drudgery that computers excel at handling. There are two categories of dynamic routing protocols: interior and exterior. In this recipe, we shall look at Routing Information Protocol, the simplest interior routing protocol. RIP is included in the Quagga suite of routing protocols.

Installation is boringly easy:

	# aptitude install quagga

Now, you must edit some configuration files. Start with /etc/quagga/daemons, and enable zebra and ripd:

	##/etc/quagga/daemons
	zebra=yes
	bgpd=no
	ospfd=no
	ospf6d=no
	ripd=yes
	ripngd=no
	isisd=no

Next, create /etc/quagga/zebra.conf:

	!/etc/quagga/zebra.conf
	hostname router1
	password bigsecret
	enable password bigsecret
	service advanced-vty
	log file /var/log/quagga/zebra.log
	!
	!administrative access controls- local machine only
	!
	access-list localhost permit 127.0.0.1/32
	access-list localhost deny any
	!
	line vty
	  access-class localhost

Now, create /etc/quagga/ripd.conf:

	!/etc/quagga/ripd.conf
	hostname router1
	password moresecret
	enable password moresecret
	router rip
	network eth1
	redistribute static
	redistribute connected
	service advanced-vty
	log file /var/log/quagga/ripd.log
	!
	!administrative access controls- local machine only
	!
	access-list localhost permit 127.0.0.1/32
	access-list localhost deny any
	!
	line vty
	  access-class localhost

And now, set correct ownership and file permissions:

	# chown quagga:quagga ripd.conf zebra.conf
	# chown :quaggavty vtysh.conf

Add these lines to /etc/services:

	zebrasrv     2600/tcp    # zebra service
	zebra        2601/tcp    # zebra vty
	ripd         2602/tcp    # RIPd vty

Finally, add this line to /etc/environment:

	VTYSH_PAGER=more

Now, fire it up:

	# /etc/init.d/quagga start

Do this on all of your routers, and you're finished.

Give it a couple of minutes, then fire up your favorite command to view your routing table:

	$ /sbin/route
	$ ip route show
	$ netstat -rn

Discussion

Quagga's configuration files use exclamation marks for comments.

All of the Quagga daemons are controlled from a single startup file:

	# /etc/init.d/quagga {start|stop|restart|force-reload| [daemon]}

You could do no more than this recipe and be content. Each Quagga daemon broadcasts its routing table every 30 seconds via multicast to your other RIP-enabled routers, and so you don't have to hassle with creating static routes all over the place.

Debian, by default, limits vty access to the local machine in /etc/quagga/debian/conf, and Fedora uses /etc/sysconfig/quagga. See Recipe 6.10 to learn how to enable remote logins.

Some definitions for ripd.conf:

hostname

This is arbitrary, and has nothing to do with the router's Linux hostname. It controls the hostname you see displayed on the vtysh or telnet command line.

router rip

Specify the rip routing protocol here. The default is to send v2 and receive 1 and 2. Other protocol options are ripng, ospf, ospf6, and bgp, which of course you would use in their respective configuration files.

network eth1

Which interface or interfaces ripd should listen on. Name additional interfaces on separate lines.

redistribute static

Share any static routes; these are listed in zebra.conf.

redistribute connected

Share directly connected routes. For example, your router is connected to the 10.0.0.1/24 network, so it will tell your other routers how to get to it.

service advanced-vty

Enables advanced vty functions such as command history and tab-completion.

access-list

The two access-list lines define a new class, localhost. The class name can be anything you want; it doesn't have to be localhost. After defining the class, the

	line vty
	  access-class localhost

lines mean "only allow vty logins on the local machine. No remote logins allowed."

The default logging level is debugging, which creates the most output. You may specify any of the following loglevels: emergencies, alerts, critical, errors, warnings, notifications, information, or debugging, like this:

	log file /var/log/quagga/ripd.log warnings

If you don't have a logfile, a crash will generate a /var/tmp/quagga.[daemon name]. crashlog file. This must be deleted to allow new crashlog files to be generated.

RIP has two versions. RIPv1 is pretty limited, and should be avoided if possible. It does not support classless network notation, and is slow to respond to changing conditions such as a down router. RIPv2 understands classless notation, doesn't get stuck in low gear, and uses triggered updates for quick responses to changes. It is compatible with RIPv1, in case you're stuck with some really old gear. The default is to send v2 and to receive 1 and 2. The version 2 option tells it to send and receive v2 only.

RIP is limited to 15 hops, so it's no good for large complex networks.

Quagga includes five routing daemons: ripd, ripngd, ospfd, ospf6d, and bgpd, and one manager daemon, zebra. zebra must always be started first. Each daemon has its own port that it listens on:

	zebrasrv     2600/tcp
	zebra        2601/tcp
	ripd         2602/tcp
	ripngd       2603/tcp
	ospfd        2604/tcp
	bgpd         2605/tcp
	ospf6d       2606/tcp
	ospfapi      2607/tcp
	isisd        2608/tcp

See Also