Ralf Weber wrote: >> It should be noted that unicast TCP is unstable if unicast routing >> is unstable. > > Yes, but TCP usually adapts to the problem while anycast can't, as it > may reach another target.
That unicast TCP fails in unusual cases means we, anyway, need retry mechanisms, which helps anycast TCP. > As someone who has deployed anycast DNS > within a carrier network there are some things to consider , e.g don't > put anycast routes in fast converging routing protocols and be careful > with multi links for similar destinations. But if you follow the rules > it can be deployed and also works with tcp transport for DNS....at > least for me. Could you elaborate on how fast converging routing protocols can be a problem? Anycast TCP fails only when route changes upon a link failure or recovery. So, anycast TCP should fail regardless of how quickly or slowly the route changes, shouldn't it? I can understand that, with multi links, packet-wise load balancers disturbing packet ordering within TCP streams are, of course, harmful to anycast TCP. Masataka Ohta _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop