[sdnog] using RIPE atlas to check which DNS root your resolver prefers.

[tariq198487]

This is very interesting 

I cannot see my probes at canar HQ,  tomorrow I will  check
Regarding Ethiopian DNS,  I think there is required config from operators as received routes from SIXP are not advertized to Ethiopian VRF. 

Thanks nishal to share this with us. 



-- 
Tarig Yassin
SudanNishal Goburdhan <nishal at controlfreak.co.za> wrote:
some of you may remember me showing some graphs from the RIPE atlas probes, showing DNS performance.  we've distributed several probes in sudan, and i thought it would be interesting for you to see what these can show you about the networks that the probes are attached to.  

if you look at:  https://atlas.ripe.net/contrib/root_anycast.html?msm_id=1 and choose "e.root" and "IPv4", you'll see that all the results for the probes in sudan, report KRT.  that's good;  it tells us that from the different network operators that have probes installed, DNS responses to e.root goes "local" to khartoum.  this is what we want!

in looking at this map, i noticed some oddities;  for example, if you look at the probes in ethiopia, you'll see a response for SDB;  which is a location in cape town.  so DNS resolution for the probes in those ethiopian networks, goes all the way to cape town.  that's clearly not very optimal.
what's likely happening, is that ethiopia telecom, buys IP transit from seacom, who also buy transit from a south african ISP, who advertises the e.root prefix to seacom.  seacom then route down to south africa to what they believe to be the closest e.root.  

i call this odd, since, at least one sudanese operator is selling IP transit to ethio telecom, so i would expect the ethio telecom probe to also pickup the e.root from khartoum.  perhaps if the operator is here, and listening, they can look into this  ;-)

you can have a lot more fun (and learn a lot more about how things route across the 'net, using the RIPE atlas probes.  you'll see that there aren't a lot of probes installed in sudan;  it would be really good to get this from as many (network) locations  as possible.  so if you want to help host a probe, please ping me (or sara) off-list.  

--n.
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