A method for processing routing information using a flooding distance vector routing protocol in which routing update messages specifying reachability information are flooded throughout a network, the method comprising, at a first router: receiving, from a second router, a router advertisement message that includes reachability information specifying at least one reachable destination and a corresponding first cost, and an originating router identifier indicating an originating router other than the second router having originated the reachability information based on local link state information of the originating router; disregarding the router advertisement message based on determining the originating router identifier specified in the router advertisement message corresponds to the first router, and based on determining the originating router identifier specified in the router advertisement message does not correspond to the first router: determining for said at least one reachable destination a corresponding second cost for reaching the reachable destination by the first router, based on the corresponding first cost; generating a second router advertisement message, based on the router advertisement message, that includes second reachability information specifying said at least one reachable destination and the corresponding second cost, and the originating router identifier received in the router advertisement message; and outputting the router advertisement message and the second router advertisement message to one or more adjacent routers according to the flooding distance vector routing protocol. receiving, from a second router, a router advertisement message that includes reachability information specifying at least one reachable destination and a corresponding first cost, and an originating router identifier indicating an originating router other than the second router having originated the reachability information based on local link state information of the originating router; disregarding the router advertisement message based on determining the originating router identifier specified in the router advertisement message corresponds to the first router, and based on determining the originating router identifier specified in the router advertisement message does not correspond to the first router: determining for said at least one reachable destination a corresponding second cost for reaching the reachable destination by the first router, based on the corresponding first cost; generating a second router advertisement message, based on the router advertisement message, that includes second reachability information specifying said at least one reachable destination and the corresponding second cost, and the originating router identifier received in the router advertisement message; and outputting the router advertisement message and the second router advertisement message to one or more adjacent routers according to the flooding distance vector routing protocol. determining for said at least one reachable destination a corresponding second cost for reaching the reachable destination by the first router, based on the corresponding first cost; generating a second router advertisement message, based on the router advertisement message, that includes second reachability information specifying said at least one reachable destination and the corresponding second cost, and the originating router identifier received in the router advertisement message; and outputting the router advertisement message and the second router advertisement message to one or more adjacent routers according to the flooding distance vector routing protocol.