25 Oct

NIXI root DNS servers and updates

Has been a while since I checked the status of root servers which are hosted at NIXI. The list as per their official member list stays the same i.e i root in Mumbai, K root in Noida and F root in Chennai. 

i root seems to be up!

K root seems to be down!

F root seems to be up!

Atleast while 2 out of 3 root servers seems to be up but for some reason my connection in Haryana isn’t  hitting i root. F root instance it is taking me there for sure. 

i root latency check from my home: 

That’s clearly too high latency. Latency from my location to Mumbai is typically 30-40ms. Let’s trace to the i root. 

Thus Airtel is taking me to all the way to London (while LNX = Airport code for Smolensk Airport, Smolensk, Russia but route clearly shows it’s being exchanged at LINX. Someone in Netnod got into habit of writing LINX as LNX which is confussing). 

I see the same by querying id.server and hostname.bind in CHAOS class.

So, for now, Airtel is preferring route learnt via LINX peering over route learnt at NIXI. In a check by all Indian RIPE Atlas probes, I see that out of 50 RIPE Atlas probes, 23 are hitting s1.mum in Mumbai, 19 are hitting LINX London (s1.lnx) and 1 (which is hosted on NKN) is hitting s1.amx in Amsterdam (json data here). 

Why this happens? 

It’s often the lack of peering and/or case of prefered routes. For smaller networks, it’s simply missing peering. For larger networks, it’s about which route they prefer, which not. Here’s a view of networks with their ASNs sorted by latency (wherever RIPE Atlas Probe) was present (measurement link here). 

So what can be done about it? 

NIXI needs to be more attractive to various (smaller) networks which clearly it is not since it just does not has any content player connected to it due to policy issue. Furthermore customers of Airtel need to buzz it and request for a better route to i root’s local instance. 

Comments & thoughts expressed in the post are personal and have nothing to do with my employer. I am also volunteering for supporting tech platform for BharatIX to facilitate peering.

06 Jul

ISC F root server – IPv6 issue at NIXI Chennai

Last week I noticed that F root was showing poor connectivity with Indian RIPE Atlas probes for F-root. The graph looked really terrible.

 

 

 

I traced to it from one of RIPE Atlas probes and saw this trace:

 

Here the last hop before timeout i.e hop 6 is of NIXI Chennai peering subnet 2001:de8:1:2::/64. As soon as I saw it, it reminded me older issue which happened and broke IPv4 connectivity to root DNS servers. I blogged about it here, here and here. So the problem remains that NIXI is broken cost wise due to charge on in – out policy. This leads to people accepting routes at all NIXI’s but they do not announce their routes. Thus return path is broken and essentially traffic is being blackholed. Earlier this issue was fixed by adding IP transit support to these root DNS servers so that a default route stays in case of all other failures.

It seems like same is missing in IPv4 world and routes are not being announced.

During this time, I saw two BGP sessions at NIXI Chennai for F root:

2001:de8:1:2::3 24049 ESTAB 25d 3h10m 1 0 2263 0
2001:de8:1:2::4 24049 ESTAB 125d18h30m 1 0 2264 0

 

Both were announcing prefix covering F root server’s pool:

 

I posted about it on SANOG and APNIC mailing list. Though there hasn’t been any reply by ISC, Sunny from APNIC passed info to them and I noticed that prefix announcement from NIXI has been withdrawn. Connectivity to F root now works to the instances outside India.

 

 

 

Waiting to hear from ISC as of now. Time to get back to work!