Allied Telesis C613-16164-00 REV E manual Dynamic inter-VRF communication explained

Dynamic inter-VRF communication explained

Dynamic inter-VRF communication explained

The following section explains how VRF routing domain isolation is maintained, and how routes that exist in one VRF instance are leaked to another VRF instance via BGP. Only BGP can be used to dynamically leak routes from one VRF instance to another.

The Forwarding Information Base (FIB) and routing protocols

Associated with each VRF instance is an IP route table, also known as the Forwarding Information Base (FIB). When BGP address-families (associated with VRF instances) are configured, a corresponding BGP route table is created for each VRF instance on which a BGP address-family is configured.

Similarly, when RIP address-families (associated with VRF instances) are configured, a corresponding RIP route table is created for each VRF instance on which a RIP address-family is configured.

Similarly, when OSPF instances (associated with VRF instances) are configured, a corresponding OSPF route table is created for each VRF instance on which an OSPF instance is configured.

Each dynamic routing protocol automatically selects appropriate routes and copies them to the FIB.

Static and connected routes are automatically added to the FIB when they are created.

		1
	OSPF
			RIP
		address
		family		-
		red			BGP
	VRF				address
					family	-
					red	BGP
red
FIB						address	-
						family
						blue			RIP
								address
								family		-
								blue		OSPF
						VRF					2
					blue
					FIB
BGP routes copied between BGP										VRF Device
address-families to facilitate inter-VRF
communication

Page 18 Configure VRF-lite