On Thu, 30 Sep 2004, John Brown CT wrote: > Couple of points here. > > 1. Typical DNS queries are via UDP, not TCP. > Thus the noise Dean is making here about things breaking > because of TCP issues, is well noise. Noise about TCP, yes. > Keep in mind that DNS queries are UDP. The query and the response. > so a typical query is 2 packets, the ask and the answer. > > Having DNS be based on TCP would NOT scale very well. We know. As you point out, TCP is still used. > Think about > it. Before I could even make a query I would have to deal with > at least 3 packets for the TCP connection setup. Then I'd send my > query, which would also have an TCP ACK sent as well, oh then there > is the answer to the query, with yet another TCP ACK. So a single > DNS query would (at a min) take 7 packets, more likely 8 to 10, > thats 400 to 500 percent more traffic than via UDP. We know. But people still propose things that will take big packets or DNSSEC, etc. > DNS uses TCP in special cases. Some of them, but not all of them > are. 1. Packet size, 2. AXFR, 3. I think TSIG / DNS SeC stuff > > Now before Dean jumps on the See, AXFR is broke, lets understand that > AXFR doesn't happen for anycasted root servers on their PUBLIC facing > IP address. AXFR is typically going to happen on a globally unique > IP assigned to each specific Anycast'd host. Thus TCP works just > fine. Yes, I'll accept that roots can be updated via means other than AXFR and updated via other than anycasted IP addresses. > > 2. This "single router requirement" is an interesting comment. I've not > seen this in any RFC or BCP. Is there one ?? I'd hope not. A BCP/RFC for what? You mean anycast? I don't know if it is in the RFC describing anycast. However, that is obviously a requirement, as pointed out previously by others. > Having muliple routers in a mesh format is good. That means if one > router fails the other can take the traffic. No doubt. > Keep in mind that from a packet path forwarding decision process, > these routers are speaking other protocols as well. There is dynamic > information being shared between these closely coupled routers that > lets them do the right thing. Really? And what protocols are those? --Dean _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf