Afrihost + Google DNS Routing

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Praemon

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Afrihost + Google DNS Server Routing (8.8.8.8/8.8.4.4)

Hey all,

Hoping to get some opinions from those more in the know. Okay, so on Afrihost, when pinging the Google DNS (8.8.8.8) it routes internationally (around 150ms). However, when pinging it from any other ISP, such as Webafrica, I get a response of around 24ms. I believe sometime in December a local cache was created, which is why there's better response times.

So, my thinking is that Afrihost needs to update their routing so that when using Google DNS, all queries hit the local cache, which should speed things up (I know it's slight, but it's still an improvement). I emailed Afrihost on 15 Dec., but got no further response other than they're looking into it. So I tweeted them today, and the Afrihost rep. insists that they are using a local Google DNS cache for the Google DNS queries, and pinging it/tracert won't give the actual route. I'm no network engineer, but how is that at all possible? Could someone provide more insight into this, because from my (basic) understanding, the packet is going to follow the same route as the ICMP ping? Or can the lookup to the DNS server route differently?

Here's the conversation on Twitter: https://twitter.com/denouncer/status/563292726977122304
 
Last edited:
Depends weather mtn peers at napafrica. Mtn does not have an open peering policy.
 
Once a bgp session is established with google, the ISP's IP addresses basically are marked as "ZA". Then when your computer queries your ISPs DNS severs for e.g mail.google.com, the dns sever will receive the nearest cluster for the ISPs range or ASN.
 
paul5186 said:
Once a bgp session is established with google, the ISP's IP addresses basically are marked as "ZA". Then when your computer queries your ISPs DNS severs for e.g mail.google.com, the dns sever will receive the nearest cluster for the ISPs range or ASN.
Click to expand...

But isn't that how the CDN operates for delivering content, not the actual DNS server request?

Afrihost is insistent that they use the Google DNS local cache server, but doing a basic dig on Afrihost vs. Webafrica clearly shows that's not the case:

Afrihost:

dig @8.8.8.8 www.afrihost.com | grep "Query time:"
;; Query time: 160 msec

Webafrica:

dig @8.8.8.8 www.afrihost.com | grep "Query time:"
;; Query time: 0 msec


If it is a peering issue as mentioned above, then I guess it won't be resolved anytime soon. Just wonder why they keep saying that they use the local servers. I can only assume the rep doesn't understand what I'm asking, and thinks I'm referring to the Google CDN.
 
Denouncer said:
But isn't that how the CDN operates for delivering content, not the actual DNS server request?

Afrihost is insistent that they use the Google DNS local cache server, but doing a basic dig on Afrihost vs. Webafrica clearly shows that's not the case:

Afrihost:

dig @8.8.8.8 www.afrihost.com | grep "Query time:"
;; Query time: 160 msec

Webafrica:

dig @8.8.8.8 www.afrihost.com | grep "Query time:"
;; Query time: 0 msec


If it is a peering issue as mentioned above, then I guess it won't be resolved anytime soon. Just wonder why they keep saying that they use the local servers. I can only assume the rep doesn't understand what I'm asking, and thinks I'm referring to the Google CDN.
Click to expand...

A google cache is different to actually peering with google. A google cache can be something simple like serving google search and youtube with servers in a location. Peering is the exchanging of all prefix's belonging to Google's ASN with your ISP's ASN.
 
paul5186 said:
A google cache is different to actually peering with google. A google cache can be something simple like serving google search and youtube with servers in a location. Peering is the exchanging of all prefix's belonging to Google's ASN with your ISP's ASN.
Click to expand...

Okay, so basically Webafrica peers with Google, but Afrihost doesn't, which is why the Google DNS servers respond locally for WA but not AH? But either way, AH is saying they route locally for Google DNS servers, which clearly isn't the case, unless I'm missing something (regardless if it's done through direct peering or a local cache).
 
Denouncer said:
Okay, so basically Webafrica peers with Google, but Afrihost doesn't, which is why the Google DNS servers respond locally for WA but not AH? But either way, AH is saying they route locally for Google DNS servers, which clearly isn't the case, unless I'm missing something (regardless if it's done through direct peering or a local cache).
Click to expand...

Google peers at Napafrica JHB and Webafrica also peers there, no MTN. One cannot route locally if you are not receiving the prefixes for Google e.g 216.58.223.0/24 locally instead of internationally. Their DNS severs may be using the google cache for DNS, but this will only provide maybe quicker dns queries and reliability, it will not make user A connecting to mail.google.com to route locally as DNS cannot do that.
 
paul5186 said:
Google peers at Napafrica JHB and Webafrica also peers there, no MTN. One cannot route locally if you are not receiving the prefixes for Google e.g 216.58.223.0/24 locally instead of internationally. Their DNS severs may be using the google cache for DNS, but this will only provide maybe quicker dns queries and reliability, it will not make user A connecting to mail.google.com to route locally as DNS cannot do that.
Click to expand...

So we're all in agreement here though, right? :) Afrihost can't be routing ICMP packets one way, and then DNS queries another, when transmitting between Google DNS servers: 8.8.8.8 and 8.8.4.4. Pinging those ip addresses should be a direct reflection of the routing, regardless of the request (I don't think it's impossible, but doesn't seem to be the case here).
 
Denouncer said:
So we're all in agreement here though, right? :) Afrihost can't be routing ICMP packets one way, and then DNS queries another, when transmitting between Google DNS servers: 8.8.8.8 and 8.8.4.4. Pinging those ip addresses should be a direct reflection of the routing, regardless of the request (I don't think it's impossible, but doesn't seem to be the case here).
Click to expand...

Correct, routing and DNS are totally separate things.
 
paul5186 said:
Correct, routing and DNS are totally separate things.
Click to expand...

Bit of an odd reply there. I think we may be missing each other :). I've been explicitly referring to routing this whole thread, including my last post. How the DNS operates and what it returns is irrelevant, as all I'm looking at is what route the packet (which happens to contain a request to resolve a hostname) takes to 8.8.8.8 from my PC on different networks.

But regardless, the main thing I wanted to find out was whether Afrihost could create some special routing to an IP address that couldn't be seen via a basic ping, and that doesn't seem to be the case. So the rep is likely mistaking my questions as something about how the local Google CDN operates rather than the response time from the Google DNS servers. Guess I just need to change ISPs, as they can't resolve it without peering at Napafrica, and that probably won't happen anytime soon.

Appreciate everyone's responses.
 
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