Poor DNS for IPv6 on Cloudflare Gateway in Australia (ISP Telstra)

I am trying out Cloudflare Gateway on Cloudflare Teams for my home network. I’ve set up the DNS issued on my home gateway to point to the Cloudflare Gateway DNS servers as per the instructions for both IPv4 and IPv6.

The IPv4 DNS queries are sent to a local location in Australia, and return DNS queries as if in Australia - eg CDN addresses.

However IPv6 DNS routes to a location in the US, and returns DNS queries as if outside Australia. For example, AWS Cloudfront IP addresses returned for a domain name are in the US.

So not only are the IPv6 DNS queries slow due to the high latency, it also returns CDN locations that are far away to make latency even worse! There are no issues if using the general Cloudflare IPv6 DNS addresses with local routing and local addresses returned.

I haven’t put my IPv6 DNS address in here as it’s personal to me. ISP is Telstra NBN. It’s like the DNS IPv6 address isn’t advertised locally or not accepted. Odd because the reverse happens elsewhere for some CloudFlare services and Telstra (IPv6 good, IPv4 not).

Seems really odd wish I had known this was happening sooner, any service on IPv6 is going to really suffer.

Out of curiosity, how have you determined this in both cases?

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Actually I’m not sure if the location is the US for IPv6 - traceroute is very lossy, but given the ping times, it certainly doesn’t look like it’s in Australia! RTT > 100ms vs 8ms for Cloudflare’s general IPv6 DNS address.

Cloudflare Gateway DNS IP, last bytes removed, should be routing to the same location, ping times the same. Other times it’s been around 100ms, still quite high.

Ping statistics for 2a06:98c1:54:::
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 280ms, Maximum = 281ms, Average = 280ms

Cloudflare general DNS IP

Ping statistics for 2606:4700:4700::1111:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 8ms, Maximum = 11ms, Average = 8ms

IPv4 Gateway DNS, also 8ms

Ping statistics for 172.64.36.1:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 7ms, Maximum = 10ms, Average = 8ms

Can you post a traceroute to both IPv4 and IPv6?

Gateway IPv6 - transported over Telstra International to somewhere outside AU (I think) - quite a bit of loss.

Tracing route to 2a06:98c1:54::x over a maximum of 30 hops

  1     2 ms     3 ms     3 ms  2001:8003:x
  2     9 ms     8 ms     8 ms  2001:8003:0:bdf:f0:3:1:0
  3     8 ms     8 ms     7 ms  ae251.lon-ice301.melbourne.telstra.net [2001:8000:0:2040:310:429::]
  4     *        *        *     Request timed out.
  5     *        *        *     Request timed out.
  6     *        *        *     Request timed out.
  7     *        *        *     Request timed out.
  8   113 ms   113 ms   110 ms  2403:e800:fd12:1002::1
  9   131 ms   114 ms   113 ms  2403:e800:ff00:110::80
 10   110 ms   110 ms   111 ms  2403:e800:fd32:1001::1
 11     *      184 ms     *     2403:e800:508:100::c2
 12   110 ms     *      110 ms  2a06:98c1:54::x

Gateway IPv4 DNS - locally routed by Telstra to Cloudflare.

Tracing route to 172.64.36.1 over a maximum of 30 hops

  1     1 ms     1 ms     1 ms  TELSTRA-MODEM [192.168.0.1]
  2     7 ms     7 ms     8 ms  gateway.vb01.melbourne.asp.telstra.net [58.162.26.193]
  3     8 ms     8 ms    11 ms  ae251.lon-ice301.melbourne.telstra.net [203.50.62.148]
  4    21 ms    18 ms   145 ms  bundle-ether25.exi-core10.melbourne.telstra.net [203.50.61.128]
  5     9 ms     7 ms    10 ms  bundle-ether1.lon-edge901.melbourne.telstra.net [203.50.11.108]
  6    10 ms     8 ms     9 ms  clo2241358.lnk.telstra.net [139.130.67.10]
  7     9 ms    23 ms     8 ms  172.64.36.1

and general CloudFlare IPv6 DNS - locally routed by Telstra to Cloudflare.

Tracing route to one.one.one.one [2606:4700:4700::1111]over a maximum of 30 hops:

  1     1 ms     1 ms     1 ms  2001:8003:x
  2    13 ms    19 ms    14 ms  2001:8003:0:bdf:f0:3:1:0
  3     9 ms     8 ms     8 ms  2001:8000:0:2040:12b:310::
  4     9 ms    17 ms     9 ms  ae20-20.win-ice301.melbourne.telstra.net [2001:8000:0:2040:12b:429:0:1]
  5     *        *        *     Request timed out.
  6     8 ms     9 ms     8 ms  bundle-ether1.lon-edge901.melbourne.telstra.net [2001:8000:0:2040:201:420:0:2]
  7    10 ms     9 ms     9 ms  clo2241358.lnk.telstra.net [2001:8000:104:21b::2]
  8     9 ms     8 ms     8 ms  one.one.one.one [2606:4700:4700::1111]