A method of controlling transmission of link state messages of a flooding-based link-state routing protocol, the method comprising: establishing a link-state routing adjacency between a first router and a second router over a layer-two, "L2", communication medium; receiving, with the first routing device, an inbound message from the second router in accordance with the flooding-based link state routing protocol, wherein the inbound message specifies a minimum packet interval for the routing adjacency between the first router and the second router and wherein the inbound message further specifies a packet credit allocated to the adjacency by the second router; and determining, with the first router, whether the L2 communication medium comprises a multi-access communication medium or a point-to-point communication medium, when the L2 communication medium comprises a point-to-point communication medium, operating the first router in a first mode in which the first router outputs the plurality of link state messages with the first router to the L2 communication medium with a time interval between successive packets that exceeds the minimum packet interval for the adjacency and up to the allocated packet credit and waiting until additional credit is received from the second router before flooding a remaining portion of the plurality of links state messages; and when the L2 communication medium comprises a multi-access communication medium, operating the first router in a second mode in which the first router: (a) identifies a longest minimum packet interval specified by any router within a group of routers having adjacencies with the first router and reachable through the same L2 communication medium, and (b) floods the plurality of link state messages with the first router to the L2 communication medium with a time interval between successive packets that exceeds the identified minimum packet interval for the group of routers. establishing a link-state routing adjacency between a first router and a second router over a layer-two, "L2", communication medium; receiving, with the first routing device, an inbound message from the second router in accordance with the flooding-based link state routing protocol, wherein the inbound message specifies a minimum packet interval for the routing adjacency between the first router and the second router and wherein the inbound message further specifies a packet credit allocated to the adjacency by the second router; and determining, with the first router, whether the L2 communication medium comprises a multi-access communication medium or a point-to-point communication medium, when the L2 communication medium comprises a point-to-point communication medium, operating the first router in a first mode in which the first router outputs the plurality of link state messages with the first router to the L2 communication medium with a time interval between successive packets that exceeds the minimum packet interval for the adjacency and up to the allocated packet credit and waiting until additional credit is received from the second router before flooding a remaining portion of the plurality of links state messages; and when the L2 communication medium comprises a multi-access communication medium, operating the first router in a second mode in which the first router: (a) identifies a longest minimum packet interval specified by any router within a group of routers having adjacencies with the first router and reachable through the same L2 communication medium, and (b) floods the plurality of link state messages with the first router to the L2 communication medium with a time interval between successive packets that exceeds the identified minimum packet interval for the group of routers.