Moin! On Aug 26, 2008, at 02:15 , Masataka Ohta wrote: > Could you elaborate on how fast converging routing protocols can > be a problem? Well I believe it was in our case as we did observe some strange behaviour when starting to test with anycast DNS.
> 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? A link failure always is the root of all evil, but we observed different behaviour of anycast and unicast tcp with it. Let me tell you what we observed. In one of our initial test setups the anycast addresses where announced with our internal routing protocol on the router that connected the anycast server. Now the link had duplex mismatch between the router and the server and thus the link flipped several times per second. While we could reach the box on it's unicast address with tcp (ssh) and got some answers over udp, we couldn't do a tcp connection to the anycast address on it no matter how hard we tried. We then changed the design so that the server itself announces the anycast addresses via an external routing protcol (BGP) and didn't have the problem above even on a deliberately duplex mismatched link. So long -Ralf --- Ralf Weber Platform Infrastructure Manager Colt Telecom GmbH Herriotstrasse 4 60528 Frankfurt Germany DDI: +49 (0)69 56606 2780 Internal OneDial: 8 491 2780 Fax: +49 (0)69 56606 6280 Email: [EMAIL PROTECTED] http://www.colt.net/ Data | Voice | Managed Services ***************************************** COLT Telecom GmbH, Herriotstraße 4, 60528 Frankfurt/Main, Deutschland * Tel +49 (0)69 56606 0 * Fax +49 (0)69 56606 2222 * Geschäftsführer: Albertus Marinus Oosterom (Vors.), Rita Thies * Amtsgericht Frankfurt/Main HRB 53898 * USt.-IdNr. DE 220 772 475 _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
