Eliot, > Yakov Rekhter wrote: > > Just because you piggyback control information on data does not > > change the fact that this is control information, and thus > > has to be processed by the control plane. > > True, but let's not get hung up just yet on how we process control plane > information.
Ok, let's gloss over details... After all, it is precisely in the details where the devil is... > >> By doing this, a failure on the part of one of the > >> far end ITRs can be transmitted to the near end ETR using those bits. > >> Similarly, when a failed far end ITR returns to service, it or another > >> far end ITR can indicate its reachability. Now, tell me how fast can > >> BGP handle either a withdraw or an announcement? > >> > > > > What matters is how fast one could restore reachability, as the > > service is reachability, not BGP. > > Right. But I'm looking for a comparison between methods to restore > reachability ;-) So am I. > > With LISP in order to restore reachability the failure information > > has to be propagated from ETRs all the way to ITRs. > > Well, let's put this in more quantifiable terms. Link goes down. IGP > floods that to other ETRs as traffic shifts from one ETR to another. > Let's agree that IGP has to converge no matter whether we're talking > LISP or BGP ;-) Now it is a mere matter of 1/2 RTT between the new ETR > and ITR. So, when you say "all the way", sure. But put in terms of > time, I'd like to understand the numbers, especially if the router has > failed. A count to infinity is not fun. I've tried it ;-) Consider a multi-homed site connected to two ISPs, ISP1 and ISP2. The ETRs are maintained by ISPs. How would you get the information about ETR failure via IGP in this scenario ? > > In contrast > > to this, with the current routing restoring reachability may require > > (much) narrow scope of the the failure information propagation. > > > > This has always been an option, but it's not solely used by any serious > enterprise. You are mistaken - this is exactly how the Internet routing system works today. Specifically, the time to restore reachability is less then the time it takes to propagate the failure information Internet-wide. > So why do you think it will be acceptable in the future? Because it works. Yakov. -- to unsubscribe send a message to [EMAIL PROTECTED] with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg
