Cisco – OSPF LSA maximum age (max age) default value

ciscoospf

Cisco in its documentation says: (Emphasis mine)

After a default of 30 minutes the router that originated the entry resends the LSA, with a higher sequence number, in a link-state update
(LSU), to verify that the link is still active.
If the LSA were to reach its maximum age (max age) of 60 minutes, it would be discarded

in OSPF: Anatomy of an Internet Routing Protocol – Page 160

When an LSA reaches the age of MaxAge (60 minutes), it is removed from consideration by the OSPF routing calculation. ..

In CCNP Authorized Self-Study Guide: Implementing Cisco IP Routing (ROUTE)

in one paragraph it says the same thing as 60 minute and somewhere else it points 4 LSDB refresh timer which equals to 120 minutes is the max age timer`

In for Dummies it says: For Dummies

Because a router expects to receive updates every 30 minutes, you may be wondering what happens if an update does not show up on schedule. If an update is not received within four intervals (120 minutes), the router is aged out of the topology database. This might happen if something unexpected happens to the router, such as a power supply failure or becoming unplugged.

Which one is true??? Is OSPF MaxAge 60 minutes or 120 minutes??

Best Answer

OSPF MAXAGE is 3600 seconds (1 hour).

Quoting from RFC 2328 - OSPFv2; Appendix B "Architectural Constants"

MaxAge
    The maximum age that an LSA can attain. When an LSA's LS age
    field reaches MaxAge, it is reflooded in an attempt to flush the
    LSA from the routing domain (See Section 14). LSAs of age MaxAge
    are not used in the routing table calculation.  The value of
    MaxAge is set to 1 hour.)

Finally, a useful google query in case you're interested in how I found the first link... ospf lsa maxage

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