OSPF E2 and N2 routes



  • JoeMJoeM ✭✭✭

    but in newer IOSs routers consider the metric to the forwarder address if it is presented.

    I disproved this in my previous debug.   I added 1,000 to the direct NSSA leg, and it does not care. 

                     forwarding address is through NSSA area.

    When I used the compatible command, it chose the E2 lsa -- but for some reason, both rfc's found/took the direct leg with the higher forwarding metric.


    For your issue, I believe that the debug command is your friend.  It will remove all of the guess-work about what is happening.  It will be helpful to all of us, if you could show this.

        debug ip ospf spf


    @martinl, thanks for that command to identify which rfc is being respected.  That will be useful.


  • timaztimaz ✭✭

    Well, I found another IOS that supports command compatible rfc1587. and it did change N2 into E2. what to look for? Line: Supports NSSA
    (compatible with RFC xxxx)
    in sh ip ospf | in  NSSA  from IOS c7200-adventerprisek9-mz.152-4.S5.

    Now, since Lab is based on IOU/IOL, I wonder about those devices.


    Cisco did really great job in releasing Cisco VIRL. because there was IOU everywhere but you cannot find a man who confesses that he uses it and declines to share what is illegal to share, but not illegal to use illegally !!! finally with releasing VIRL, Cisco decided to sell virtualized L2/L3 IOSs and ASA and it is time for great things about labbing. I've not had IOU and don't know how it works, but with VIRL we are all happy now. besides I don't have VIRL too by now and have to work with GNS anyway. 

    if you had a chance to work with IOS that supports "comptible rfc" command and it made the router to select E2 over N2 regardless of any kind of metric, then it means it works well. 

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