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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: PMTU-D: remember, your load balancer is broken
On Sat, 17 Jun 2000 11:59:30 PDT, Paul Vixie <[email protected]> said: > [email protected] writes: > > Has this changed? Has "fragmentation" become a Great Evil, ... ? > Yes. http://research.compaq.com/wrl/techreports/abstracts/87.3.html says: (abstract trimmed) > Research Report 87/3, December 1987 > > 87.3 -- Fragmentation Considered Harmful > Fragmentation is at best a necessary evil; it > can lead to poor performance or complete > communication failure. There are a variety of Yeah, I've known about that for a while. What I *meant* was: Has fragmentation been reclassified from "necessary evil that can cause problems" to "Great Evil that must be avoided at all costs"? For instance, we probably all agree that fragging on a core router is Bad Juju and should be avoided if at all possible. On the other hand, how far should we jump through hoops (such as PMTU-D etc) to avoid fragging on a last-hop modem link from a terminal server to a PC? I already spend far too much of my day (even with a lot of tools) sending flame-grams to ISPs who drop us spam, or have open mail relays, or start running NTP or tools that query ports 13/37 and forget to open the firewall, and then complain about my machine probing them.. Enabling PMTU-D (even if it won't buy *my* boxes that much since their local MTU is 1500) and getting people to fix their ICMP configurations for the benefit of those sites that WILL profit is an option, but only if there's general consensus that it's a fight worth fighting... Valdis Kletnieks Operating Systems Analyst Virginia Tech
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