Cole Tuininga writes: > > Preface - > > The folks on the sys-admin list are talking about the migration of > services from the older server to the newer server. Of course, one of > the issues that's come up is DNS. This led to the following snippet: > > On Sat, 2006-04-08 at 09:04 -0400, wrote: > > > Well, there's at least one easy workaround for that, aside from the > > > obvious (shorten TTL ahead of time, to force fast propagation). > > > > Unfortunately, shortening the TTL doesn't work for clients (like AOL) > > that cache/maintain their own DNS. > > I was curious - how do folks in general deal with this? While AOL can > certainly constitute a large number of users, my inclination is to say > "hell with 'em". If they can't conform to proper netiquette, why should > I be bending over backwards to support them? > > I was just curious to get other folks' take on this quasi-philosophical > point.
For HTTP you can create temporary A/PTRs that have never existed then use a 302 to redirect from old to new. For example: old server has www.example.com that responds with a 302 redirecting to www2.example.com new server hosts both www and www2 with the same content. That way people with and old cache will request a new lookup for www2 (which is new and never had the old address). This of course means you need to keep the www2 name around indefinately because it could end up in people's bookmarks/links. If bandwidth isn't an issue for the short term, the better solution is to NAT requests going to the old server to the new server. Use both SNAT and DNAT in iptables to redirect important UDP/TCP ports on the old server to the new server. -- Dave _______________________________________________ gnhlug-discuss mailing list gnhlug-discuss@mail.gnhlug.org http://mail.gnhlug.org/mailman/listinfo/gnhlug-discuss
