On Thu Sep 3 15:31 , Justin Shore sent: >I'm soliciting suggestions on the pros and cons on the assortment of >ways to inject customer routes into iBGP at the edge. > >One could simply reference prefix-lists in the BGP config on a >per-neighbor basis (or peer-group). The downside to this is that >prefix-lists can't haven't inline comments for storing information about >the individual prefixes. As the prefixes on the edge grow I would think >that admin overhead and potential for errors would grow as well. > >I could reference route-maps in the BGP config as well (per >neighbor/peer-group). I'm doing this today, matching against a >prefix-list to get my routes. The upside is I add a new sequence to the >route-map per customer and create a uniquely-named prefix-list per >customer. This of course requires more config and more potential typos >but makes changes as customers come and go much more clearcut (ie, there >is no question which prefixes belong to which customer). Another upside >is that I can also put specific communities on prefixes with a >route-map. I'm not doing this today but I plan to in the future as my >BGP community design progresses.
I prefer using your second option. Whether in an ISP (with customer routes) or a large enterprise (with lots of business partners), I like the use of prefix-list for the exact reason you stated; labeled by customer/business partner name, route-maps (ditto; labeled by customer/business partner name). This gives you alot of flexibility to tag or influence behavior and policy by altering options within the route-map for both incoming and outgoing routing policies. I think this format also makes it easier on your operations folks since you've named the prefix-lists and route-maps associated with each customer/business partner. -chris > >A third option is redistributing statics into BGP. This gives me the >opportunity to tag specific prefixes and filter them with a route-map so >I only redistribute the prefixes that I want redistributed. I can also >name static routes. I need a static route anyway to tack up the route >for outbound advertisement and to prevent loops. The downside is that I >hate using redistribution. I'm not a big fan of it. I've been bit too >many times to consider redistribution a good method of doing anything. >It will also result in higher CPU load as the RIB is frequently parsed >for statics and processed with the route-map if I'm not mistaken. >Correct? > >A fourth option would be to use distribute-lists. I can use remarks to >label my individual prefixes in the ACL which is good but I end up with >one large distribute-list ACL for all my customer prefixes. That means >any errors could affect all customers at once. I also don't end up >using route-maps so I don't get to set communities on advertised prefixes. > >And finally I could use a combination of any of the above to accomplish >my goals. > > >What methods do my SP colleagues prefer to use when managing the >injection of customer routes into iBGP? I'm open to suggestions. I've >tried both of the first 2 options and lean towards the 2nd. It's time I >get the remaining customer routes out of the IGP but unfortunately I >can't see far enough ahead to decide which method is best. I can't help >but to think that there must be a better way to accomplish my goals >without increasing my work load too much and without increasing the >likelihood of making major mistakes. > >Thanks > Justin > > >_______________________________________________ >cisco-nsp mailing list [email protected] >https://puck.nether.net/mailman/listinfo/cisco-nsp >archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
