North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: /8 end user assignment?
[email protected] (Iljitsch van Beijnum) writes: > On 5-aug-2005, at 15:55, Joe Abley wrote: > > > It is of course possible to construct networks through which TCP > > behaves very poorly with anycasted services. This does not mean that > > TCP is fundamentally incompatible with anycast. > > It does mean that if people want to anycast services that run over TCP > (even just a small part of the time, such as DNS) they should make sure > this works well. it's working fine for 30+ instances of F-root. > A good start is using different AS numbers for the anycast instances so > (Cisco) routers won't load balance over the different paths. we have not encountered a problem like this, even though all F-root anycast instances use a consistent origin-AS. my belief, previously explained here, is that anyone who turns on multipath-EGP (rather than multipath-IGP) is going to have a boatload of other problems before they ever get around to noticing whether TCP is working toward anycasted servers. (OSPF ECMP is, i believe, on-by-default; multipath-BGP is, i am sure, off-by-default.) > But all of this is irrelevant to the discussion at hand, unless I missed > something big and DNS over TCP has now been deprecated. If that's the > case, the appropriate action is to disable TCP queries in the software, > not to avoid TCP queries by keeping response sizes small. agreed. (that TCP isn't a problem.) > But my original point was that you won't go over the non-EDNS0 limit > for normal queries with less than a dozen AAAA records anyway. disagreed. (because DNSSEC is coming.) -- Paul Vixie
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