Policy Routing in Multi-Arm Deployment

Hi mOjO,

using iRules its the only way setting up Policy-Based-Routing (PBR) based on SRC_IP and DST_IP. The [class match] syntax of the iRules outlines in K20510467 is just "one" example how your PBR could be setup. You may also use native [if] expressions or [switch] statement to express your needs.

When designing such a PBR, then elect to most used routing scenario as your "default" and use F5s routing table to establish the routing as usual. The use the iRule to overwrite routing decissions based on your needs.

when CLIENT_ACCEPTED {

	if { ( [IP::addr [IP::client_addr] equals "10.0.0.0/8"] )
	 and ( [IP::addr [IP::local_addr] equals "10.0.0.0/8"] ) } then {

		# Let the build-in routing table forward traffic for:
		#
		# src=10.0.0.0/8 to DST=10.0.0.0/8

	} elseif { ( ( [IP::addr [IP::client_addr] equals "172.16.0.0/12"] )
			  or ( [IP::addr [IP::client_addr] equals "192.168.0.0/24"] ) )
		   and ( ( [IP::addr [IP::local_addr] equals "172.16.0.0/12"] ) 
			  or ( [IP::addr [IP::local_addr] equals "192.168.0.0/24"] ) ) } then {

		# Let the build-in routing table forward traffic for:
		#
		# src=172.16.0.0/12 or src=192.168.0.0/24 to DST=172.16.0.0/12 or DST=192.168.0.0/24


	} elseif { ( [IP::addr [IP::client_addr] equals "10.0.0.0/8"] )
		   and ( [IP::addr [IP::local_addr] equals "20.20.20.0/24"] ) } then {

		# Overwrite next hop to GW=10.10.10.1 for:
		#
		# src=10.0.0.0/8 to DST=20.20.20.0/24

		nexthop 10.10.10.1

	} elseif { [IP::addr [IP::client_addr] equals "10.0.0.0/8"] } then {

		# Overwrite next hop to GW=10.10.20.1 for:
		#
		# src=10.0.0.0/8 to DST=REMAINING DESTINATIONS

		nexthop 10.10.20.1

	} else {

		# let the build-in routing table handle remaining traffic...

	}

}

Cheers, Kai