1.1.1.1 server in BKK (near TOT ISP) resolve Azure CDN non-optimally

Zero Trust 1.1.1.1
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1

Using TOT home fiber optic connection, 1.1.1.1 server seems to return a non-optimal IP address to software-download.microsoft.com (which seems to be on Azure CDN):

$ dig +short CHAOS TXT id.server @1.0.0.1
"BKK"
$ dig +short @1.0.0.1 a software-download.microsoft.com
18d5d.wpc.azureedge.net.
az784874.vo.msecnd.net.
cs22.wpc.v0cdn.net.
152.199.4.33

According to my traceroute, this IP seems to be in USA (which explain my terrible download speed). However, when I switched to my mobile network (AIS), 1.1.1.1 server seems to return an optimal IP address:

$ dig +short CHAOS TXT id.server @1.1.1.1
"BKK"
$ dig +short @1.1.1.1 a software-download.microsoft.com
18d5d.wpc.azureedge.net.
az784874.vo.msecnd.net.
cs22.wpc.v0cdn.net.
117.18.232.200

This server gives me a good downloading speed. I knows that 1.1.1.1 doesn’t forward client subnet. So, somehow 1.1.1.1 server near TOT gets a different response from Azure’s DNS server than the one near AIS. Could a Cloudflare engineer investigate in why this happen?

Oh, BTW, 1.1.1.1 address is unreachable from TOT home fiber optic connection, only 1.0.0.1 is.

2

Interestingly, you go in both cases to Cloudflare’s Thai datacentre.

I’d open a support ticket for that case. Also, post the ticket number here so @cloonan can keep track.