Recent LSA

[gauravprakash]

Hi,

In OSPF , if the sequence no & checksum are equal for a two LSA, Age is compared .( as per Jeff Doyl book) If only one of the LSA has MAXAGE (3600) sec, it is considered the more recent.

PLz explain what does this exactly mean. Howcome a MAXAGE LSA will be considered more recent....

[pkhatri]

Hi,

MaxAge LSAs are used, among other things, in order to pre-maturely age LSAs. That's why routers are required to treat the MaxAge LSAs as more recent. When a router receives a MaxAge LSA, it is required to purge it and therefore it dis-regards the same LSA with a lower age.

Paresh

[amms68958]

Hi,

To add to this ,it is highly improbable that 2 LSAs are having equal sequence number and checksum.

Joh Moy's book ,OSPF Anatomy of routing protocol

explains these scenarios well.

Thanks

Thomas.