On Fri, Feb 15, 2008 at 3:49 PM, Robin Whittle <[EMAIL PROTECTED]> wrote: > Marshall Eubanks wrote: > > > Note, too, that many simple web pages have in them pieces from > > other servers and other IP addresses (banner ads are frequently > > done this way) and so this could put a real performance hit on > > web page load times in the real world. > > I have been thinking of this, but this is the first mention of it on > the list. This is a typical Internet usage where people have to > wait as it is, and would be waiting longer if any of the web servers > relied on LISP-ALT ITRs which did not yet have the mapping for the > particular EID in which the client is located.
Robin, It seems to me that one assumption which has run heavily through this thread is that man-n-encap would entirely replace the existing system where the EID and LOC are the same. It strikes me that not only is this unlikely, it would be undesirable as well. I won't spend a lot of time on why outright replacing BGP is unlikely. Suffice it to say that anything the size of the Internet has a great deal of inertia and no map-n-encap scheme discussed so far has enough punch behind it. I will spend a couple paragraphs on why a hybrid system is a desirable outcome. There are relatively few scenarios in which a client machine derives a benefit from a static IP address assignment. Mobility, at least with respect to long-lived connections. The occasional firewall admin where inbound access to a resource has been restricted by source IP address. Not a whole lot else. Given a choice between a mild slowdown and the temporary assignment of an IP address from a highly aggregated pool, most clients would elect to use the temporary assignment. Servers are a whole other can of worms. There are spam filters which block and permit by IP address. There's lots of crappy software which doesn't respect DNS TTLs. Renumbering servers is a difficult and fault-ridden process. Given a choice between an extra delay equivalent to a DNS lookup on every request and having to renumber, more than a few server administrators would choose the extra delay... Especially for email servers and other devices that move data in bulk where the delay simply doesn't matter. The conclusion, it seems to me, is that the desirable outcome is a hybrid system in which a fellow in Operations can consider both PI space and Fast space, and then choose the one best suited to his particular application. In other words, whether you favor LISP or IvIP or TRRP, your system should be designed as a supplement to BGP, not a replacement. A supplement which serves to enable PI space. YMMV, Bill Herrin -- William D. Herrin [EMAIL PROTECTED] [EMAIL PROTECTED] 3005 Crane Dr. Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004 -- 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
