distribute lists

These are barely even mentioned in IRA2, but I ran across them and hadn't noticed them before.  I think I must have seen them and assumed they were the same thing as "redistribute" in the past or something.  They seem fairly simple, and as far as I can tell provide functionality that might be better handled with route-maps or prefix lists - is this correct?

Nearly all of the examples I've found for using them show how to use an ACL to match even or odd routes for filtering (including the CCIP vids and the R&S v1 lab book) for some reason.  Am I missing out on something by not using them/having a deeper understanding of them?


  • Hi,

    Distribute-list is a powerful tool for doing route filtering specially on IGPs, but can be used with BGP as well.

    You can use ACLs, prefix-lists or route-maps, it will depend on the requirement. Route-maps and prefix-lists give you more flexibility and control on what you want to filter. ACLs on the other hand are simpler to configure and understand.


    Good luck!

  • Yeah, I discovered pretty quickly after posting this that there are distribute-list labs for most of the IGPs in the v1 workbook.  I like how they've chopped up the workbook into sections now, but it makes seeing the "big picture" a little more difficult.

    I'm trying to figure out how I made it this far in my studying w/o hearing about them, but then I haven't taken any of the CCNP tests yet.

  • This is extensively covered on the ROUTE exam. Which exam are you studying for? CCIP?

    Good luck! 

  • Yeah, CCIP currently, and CCNP is next.

    I see now that I probably would have benefitted from following the standard path, but a) I like learning single subjects at a deeper level much more than learning a little bit about a hundred things at once, and b) I work at a small ISP, so the CCIP had direct and immediate use to me.  Looking around at job postings makes it pretty clear that CCNP is much more useful in an enterprise environment.

  • All It boils down to is one of route filtering mechanism available in IOS. Other available options among various protocols are:

    > Route-Map

    > Administrative Distance (AD)

    > Route Metric

    > Forwarding Address into OSPF

    > Summary Address/Area Range

    > Communities



    Deepak Arora



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