Forum Replies

  1. Hi Sims,

    Let’s say you have a small network with a couple of routers. One router is connected to an ISP router for Internet access. On this router, you could advertise a default route in your OSPF network.

    When there is no matching route in the routing table, the default route will be used and your traffic will be forwarded towards the ISP.


  2. Shawn,
    Yes, you can do this, sort of :slight_smile:

    Remember that a requirement for OSPF is that all members in the same area must have identical databases (and I presume that your DMVPN hub and spokes are in the same area). So the best you are going to be able to do is keep that default route from getting installed in the routing table, even though it will still be present in the OSPF database. I recommend using a prefix-list to do it. Here’s a sample:

    (config)#ip prefix-list PL_NODEFAULT deny
    (config)#ip prefix-list PL_NODEFAULT permit le 32
    (config)#router ospf 1
    (config-router)#distribute-list prefix PL_NODEFAULT in
  3. Andrew, that worked perfectly. Thank you so much!


  4. Hi
    What if we have different area and core distribution access layer .
    Where we have to put the default originate command

  5. I had a question.

    1. with Static default route we configure something like the following:

    ip route xxx.DestinationAddress.xxx.xxx

    1. If it was EIGRP and we had the following manually configured default route to advertise in EIGRP we would then use the following:

    R2(config)#router eigrp AS#

    with OSPF I did not see something similar is that because you just did not put in the full configuration or because OSPF just uses that statement:

    default-information originate always

    I would think it would need a manual entry for the default route to point where it is going to? such as add a default route statically after that and then this statement will advertise it. I am however, not positive because it was missing any type of manual default route in the configurations.

    I guess you state here:

    advertise a default route if you don’t already have it in your routing table. If you add the always keyword it will advertise the default route even if you don’t have it in the routing table

    I would probably have used the word create instead of advertise but after studying the statement a bit closer I get what you meant.

    This is like 4rth - 6th time I am going through the OSPF, and BGP lessons trying to drill down and get everything memorized since Sept 2017(though to be honest had a few breaks in there and forgot everything a couple times… lol) I just want to go play Total War Rome but I will keep studying as I have next two weeks off on vacation and want to put in about 40-48 hours study time each week and prep for my CCNP Route and my new job. I hope to take CCNP Route before End of 2018.

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