Cached routing table management

摘要

Techniques are provided for cached routing table management in a distributed network switch. A frame having a source address and a destination address is received. If no routing entry for the source address is found in a routing table of a switch module in the distributed network switch, then routing information is determined for the source address and a routing entry is generated. The routing table is modified to include the routing entry, based on a set of hash functions. Upon accessing the generated routing entry in the modified routing table responsive to a subsequent lookup request for the source address, the set of caches is modified to include the generated routing entry.

主权项

1. A non-transitory computer-readable medium containing a program which, when executed, performs an operation comprising:
receiving, by a first switch module of a distributed network switch, a first frame having a source address and a destination address, wherein the first switch module comprises a plurality of bridge elements and a routing table, wherein the routing table in the first switch module is shared among the plurality of bridge elements in the first switch module and includes a plurality of sets of buckets, wherein each set of buckets is associated with a respective hash function of a plurality of hash functions, wherein at least a first bridge element of the plurality of bridge elements has an associated set of caches; upon determining that the routing table in the first switch module does not include any routing entry for an address selected from the source address and the destination address of the first frame, generating, in the routing table in the first switch module, a routing entry for the selected address, based on routing information determined for the selected address and based further on at least one of the plurality of hash functions, wherein a routing entry, selected based on an aging criterion, is discarded if the routing table in the first switch module satisfies a fullness condition, wherein the first frame is forwarded based on the determined routing information and received by a second switch module of the distributed network switch, the second switch module having a routing table; upon determining that the routing table in the second switch module does not include any routing entry for the selected address, generating, in the routing table in the second switch module, a routing entry for the selected address, based on routing information determined for the selected address and based further on at least one of the plurality of hash functions; and upon accessing the generated routing entry in the modified routing table in the first switch module responsive to a subsequent lookup request for the selected address, modifying the set of caches to include the generated routing entry.