Link state identifier collision handling

摘要

Methods and apparatus for a network element to handle LSID collisions to prevent different LSAs associated with different routes from sharing the same LSID. According to one embodiment, responsive to determining that a tentative LSID that is generated for a first route that is being added collides with an LSID that is assigned to an LSA for a second route, and that one of the first and second routes is a host route, the host route is suppressed. If the first route is the host route, suppressing includes not originating an LSA for the first route. If the second route is the host route, suppressing includes purging the LSA for the second route and not originating an LSA for the second route. Although the host route is suppressed, network reachability of the range subsuming the host route is provided through the route that is not the host route.

主权项

1. A method performed in a network element implementing an Open Shortest Path First (OSPF) protocol for avoiding Link State Identifier (LSID) collisions when assigning LSIDs to identify link state advertisements (LSAs) originated by the network element, the method comprising:
originating a first LSA for a first route, wherein the first LSA includes a first LSID, and wherein the first route is a first host route having at first route mask that is a host mask; determining to originate a second LSA for a second route; generating a tentative second LSID for the second route; and responsive to the tentative second LSID being the same as the first LSID and the first route being the first host route,
suppressing the first LSA of the first route to avoid a LSID collision, andoriginating the second LSA for the second route, wherein the second LSA includes the tentative LSID.