I recently upgraded Pi-hole to 4.0 and use local unbound. Followed instruction to set qname-minimal.
Family user complains certain video streaming slowness. But super fine with mobile 4g network. As my home Internet and mobile carrier are the same ISP, I have to suspect whether CDN causes the difference.
If I setup local unbound dns, is it geolocation aware to get closest CDN server IP? Is there any special configuration required? Or unbound just no way to be compatible with CDN?
I changed pihole dns to Cloudflare. As big dns cache I haven’t felt the difference yet. Performance vs. privacy I may choose speed.
This is not a function of your DNS resolver. It's a function of the content provider determining where your requests are coming from (your ISP in this case), and routing the network traffic to the appropriate server in their system.
Unbound as a DNS resolver simply goes to the authoritative name servers and gets the IP address(es) for the domain you are looking for. When you go to that IP address in the browser or application, that's where the traffic routing occurs.
You can run a trace route or other similar tool to determine where the content is coming from.
Why did you specifically point this out? Have you tried disabling it?
It is possible that QNAME minimization can cause issues, however, I haven't heart of any reports more recently.
my understanding is if i use a CDN aware public DNS like google and CF, when I query a domain name, it will return a IP address of the CDN server which is closet to my geolocation (my DNS request source IP). domain name system - CDN: How is it possible that my DNS delivers a different IP depending on the visitors location? - Server Fault
But if I use unbound local DNS, it doesn't know my location, just give me an answer from authority.
I will test a little bit to see if using CF DNS and unbound DNS whether return different IP of same domain.
Some google results lead me to QNAME-minimization might break Akamai CDN.
www.dell.com
Server: 192.168.1.6
Address: 192.168.1.6#53
Non-authoritative answer:
www.dell.com canonical name = www1.dell-cidr.akadns.net.
www1.dell-cidr.akadns.net canonical name = cdn-www.dell.com.edgekey.net.
cdn-www.dell.com.edgekey.net canonical name = cdn-www.dell.com.edgekey.net.globalredir.akadns.net.
cdn-www.dell.com.edgekey.net.globalredir.akadns.net canonical name = e28.x.akamaiedge.net.
Name: e28.x.akamaiedge.net
Address: 23.9.146.14
www.dell.com
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
www.dell.com canonical name = www1.dell-cidr.akadns.net.
www1.dell-cidr.akadns.net canonical name = cdn-www.dell.com.edgekey.net.
cdn-www.dell.com.edgekey.net canonical name = cdn-www.dell.com.edgekey.net.globalredir.akadns.net.
cdn-www.dell.com.edgekey.net.globalredir.akadns.net canonical name = e28.x.akamaiedge.net.
Name: e28.x.akamaiedge.net
Address: 104.124.190.16
This is not really what I expect: how would the CDN provider know which IP to hand out to you? I can see how google's DNS knows which Google server is closest, e.g., in Germany, but how should it know such details for Dell servers? It is Dell's responsibility to give you an AnyCast IP address and decide themselves which server is best for you.