I don't know if this http://tools.ietf.org/id/draft-vandergaast-edns-client-ip-01.txt
is going anywhere (the latest draft has expired) but if it does then support in dnsmasq may be in order. Ed W wrote: > I have a curious problem being served sub-optimal CDN servers when using > opendns or googledns > > I am in London/UK and opendns appears not to have a local DNS cache, so > attempting to access bbc.co.uk and view the page images gives these results: > > # dig news.bbcimg.co.uk > > ; <<>> DiG 9.7.3 <<>> news.bbcimg.co.uk > ;; global options: +cmd > ;; Got answer: > ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57231 > ;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0 > > ;; QUESTION SECTION: > ;news.bbcimg.co.uk. IN A > > ;; ANSWER SECTION: > news.bbcimg.co.uk. 2413 IN CNAME newsimg.bbc.net.uk. > newsimg.bbc.net.uk. 202 IN CNAME news.bbc.co.uk.edgesuite.net. > news.bbc.co.uk.edgesuite.net. 3427 IN CNAME a1733.g.akamai.net. > a1733.g.akamai.net. 10 IN A 216.246.75.138 > a1733.g.akamai.net. 10 IN A 216.246.75.113 > > ;; Query time: 84 msec > ;; SERVER: 192.168.105.212#53(192.168.105.212) > ;; WHEN: Fri Jul 8 10:22:02 2011 > ;; MSG SIZE rcvd: 168 > > That ip range is in the USA and about 85ms away from me. > > > Instead using google dns I get: > > # dig news.bbcimg.co.uk @8.8.4.4 > .. > a1733.g.akamai.net. 19 IN A 193.28.236.135 > a1733.g.akamai.net. 19 IN A 193.28.236.136 > > These are 41ms away > > > If I switch to my ISP DNS servers: > > # dig news.bbcimg.co.uk @212.69.36.3 > .. > a1733.g.akamai.net. 15 IN A 92.123.154.18 > a1733.g.akamai.net. 15 IN A 92.123.154.33 > > These are 15ms away > > > So having discovered that using nominally faster DNS servers has amongst > other things the disadvantage that CDNs might pass you to suboptimal > choices, hurting you multiple times per web page... > > So I tried this configuration: > > server=8.8.4.4 > server=/akamai.net/212.69.36.3 > server=/edgesuite.net/212.69.36.3 > > But I notice that since the reply comes back in a single response that > the CNAMES are not resolved using the alternative server parts. Yes, that approach is not tenable. > > Disregarding all the privacy debates about using these super DNS > servers, does anyone have any thoughts on how to better handle getting > redirected to a local CDN, other than perhaps using only the ISP servers? I wonder if your ISP has a cache for the BBC content withing its network? Traffci from bbc.co.uk must make up a huge proportion of external traffic for UK ISPs. Maybe try it the other way around, (ie use openDNS or Google DNS for everything _except_ (list of big site likely to use local CDNs) Simon. > > Thanks > > Ed W > > _______________________________________________ > Dnsmasq-discuss mailing list > [email protected] > http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss >
