# /usr/local/etc/bird.conf
###################### ROUTER R1

router id 10.4.4.1

protocol kernel {
	export all;
}

protocol direct {
}

protocol device {
	scan time 10;
}

protocol static {
	route 0.0.0.0/0 via 123.123.123.1;
}

protocol ospf {
	tick 2;
	rfc1583compat yes;
	export filter {
		if net = 0.0.0.0/0 then {
			ospf_metric1 = 100;
			accept;
		}
		reject;
	}
	area 0.0.0.0 {
		interface "vtnet1" {
			dead count 4;
			type broadcast;
		}
	}
}

######################
###################### ROUTER R2

router id 10.4.4.2

protocol kernel {
	export all;
}

protocol direct {
}

protocol device {
	scan time 10;
}

protocol static {
	route 0.0.0.0/0 via 123.123.123.1;
}

protocol ospf {
	tick 2;
	rfc1583compat yes;
	export filter {
		if net = 0.0.0.0/0 then {
			ospf_metric1 = 100;
			accept;
		}
		reject;
	}
	area 0.0.0.0 {
		interface "vtnet1" {
			dead count 4;
			type broadcast;
		}
	}
}

######################
###################### ROUTER R3

router id 10.4.4.3

protocol kernel {
	export all;
}

protocol direct {
}

protocol device {
	scan time 10;
}

protocol static {
}

protocol ospf {
	tick 2;
	rfc1583compat yes;
	import filter {
		# accept only routes from R1 and R2
		if ospf_router_id = 10.4.4.1 then {
			# for R1's default route set a lower metric so it is prefered
			if net = 0.0.0.0/0 then {
				ospf_metric1 = 10;
			}
			accept;
		}

		if ospf_router_id = 10.4.4.2 then {
			accept;
		}
		reject;
	}
	area 0.0.0.0 {
		interface "vtnet0" {
			dead count 4;
			type broadcast;
		}
		interface "ng*" {
			stub yes;
		}
	}
}

######################
###################### ROUTER R4

router id 10.4.4.4

protocol kernel {
	export all;
}

protocol direct {
}

protocol device {
	scan time 10;
}

protocol static {
}

protocol ospf {
	tick 2;
	rfc1583compat yes;
	import filter {
		# accept only routes from R1 and R2
		if ospf_router_id = 10.4.4.1 then {
			accept;
		}
		if ospf_router_id = 10.4.4.2 then {
			# for R2's default route set a lower metric so it is prefered
			if net = 0.0.0.0/0 then {
				ospf_metric1 = 10;
			}
			accept;
		}
		reject;
	}
	area 0.0.0.0 {
		interface "vtnet0" {
			dead count 4;
			type broadcast;
		}
		interface "ng*" {
			stub yes;
		}
	}
}

######################