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??

  • 1
    Please avoid liberal usage of boldface font. Quote blocks are much better. May 24, 2014 at 14:29
  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Aug 8, 2017 at 18:13

1 Answer 1


OSPF MAXAGE is 3600 seconds (1 hour).

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

    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

  • WOW what a gr8 skill!! My friend your answer is rocking awesome and cool!! I believe u didn't read the question yet OR my wording is not good enough to express what I mean!!! anyway I'VE DONE THAT SEARCH LIKE U AND HAVE SEEN EM LIKE U the question is first not the RFC but the implementation of this particular subject in Cisco products, second WHY THERE IS THIS DISTINCTION BETTWEEN THOSE MENTIONED RESOURCES??? there must come from a source or deduction can't be just written like that, hope I'm clear enough
    – Mjaryan
    May 24, 2014 at 15:48
  • Note: [comments Removed] -- Please refrain from carrying on extended conversations in comments. If you have an answer, post it as an answer. Comments should generally address improvements to the original post. They're not for launching into your own tangents or debates. Please feel free to use the chat room to conduct such discussions. Thanks May 24, 2014 at 16:33
  • @mjaryan, Giuseppe Larosa's answer on the Cisco support site means that Cisco sets MaxAge to 3600 seconds. Please understand that vendors do not deviate from IETF standards on these important protocol constants. As for the odd discussions about aging the LSDB after two hours, I can only say they have nothing to do with MaxAge; furthermore they appear to conflict with RFC2328 Section 14 May 24, 2014 at 17:01

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