17 Nov

Measuring latency to endpoints with blocked ICMP

And a blog post after a while. Last few months went busy with RPKI. After my last post about RPKI and the fact that India was lacking a little bit on RPKI ROA front, we started with a major push by a set of like-minded folks like us. For now, Indian signed table has jumped from 12% since Aug to 32% now in Oct. Detailed graphs and other data can be found here on the public Grafana instance.

In terms of absolute percentage, India now has the highest number of absolute signed prefixes in this region. 13972 Indian prefixes have a valid ROA and nearest to that is Taiwan at 6824. Though 13972 results in just 32% of the Indian table while 6824 results in 91% of Taiwanese table. So a long way to go for us.

If you are a network operator in India and reading this, consider joining our RPKI webinar which is planned at 3 pm (IST) on 18th Nov 2020. You can register for the event here. Or buzz me to talk about RPKI!


Catching Covid-19

Besides RPKI push I also caught up with Covid19 along with family members. Luckily for us, it went fine and wasn’t that painful. The impact was mild and everyone has recovered. Phew!
I hope readers of this blog post are well.

TraceroutePing in Smokeping

Coming to the topic for today’s blog post. I recently came across this excellent Smokeping plugin which solves a very interesting problem. There are often nodes we see in the traceroute/MTR which is either not routed or simply block ICMP/TCP/UDP packets which are addressed to them. This can include routers which have a pretty harsh firewall dropping everything addressed to them as well as cases where we have IX or any other non-routed IP in the traceroute. It becomes tricky to measure latency to those. Someone used the simple idea of incremental TTLs as used in traceroute to get a reply from these middle nodes of “TTL time exceeded error” and based on that a way to plot latency.

Let’s look at a real-world case: One of ISP serving my home is IAXN AS134316 and they peer with my ex-employers network Spectra AS10029 at Extreme IX in Delhi. Let’s see how traceroute to Spectra’s anycast DNS looks from my home.

traceroute -P icmp 180.151.151.151
traceroute to 180.151.151.151 (180.151.151.151), 64 hops max, 72 byte packets
 1  router01.rtk.anuragbhatia.com (172.16.0.1)  2.818 ms  1.876 ms  4.274 ms
 2  10.10.26.6 (10.10.26.6)  4.258 ms  4.301 ms  5.953 ms
 3  10.10.26.5 (10.10.26.5)  5.490 ms  5.916 ms  5.257 ms
 4  10.10.26.29 (10.10.26.29)  11.349 ms  9.246 ms  9.430 ms
 5  as10029.del.extreme-ix.net (45.120.248.51)  10.628 ms  8.802 ms  9.609 ms
 6  resolver1.anycast.spectranet.in (180.151.151.151)  8.446 ms  9.113 ms  10.699 ms

Now hop 5 here is likely Spectra’s Delhi router’s interface which has Extreme IX IP – 45.120.248.51. Let’s see what we get when we ping it.

ping -c 5 45.120.248.51
PING 45.120.248.51 (45.120.248.51): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
Request timeout for icmp_seq 2
Request timeout for icmp_seq 3

--- 45.120.248.51 ping statistics ---
5 packets transmitted, 0 packets received, 100.0% packet loss

I cannot ping it. Let’s look at the trace to it to see where it drops.

traceroute -P icmp 45.120.248.51
traceroute to 45.120.248.51 (45.120.248.51), 64 hops max, 72 byte packets
 1  router01.rtk.anuragbhatia.com (172.16.0.1)  3.196 ms  1.790 ms  4.421 ms
 2  10.10.26.6 (10.10.26.6)  5.514 ms  3.624 ms  5.323 ms
 3  10.10.26.5 (10.10.26.5)  5.252 ms  4.043 ms  3.671 ms
 4  * * *
 5  * * *
 6  nsg-static-77.249.75.182-airtel.com (182.75.249.77)  14.221 ms  10.963 ms  11.574 ms
 7  116.119.68.58 (116.119.68.58)  146.531 ms  147.899 ms  146.065 ms
 8  * * *
 9  * * *
10  * * *

Now, this is an interesting and not very unexpected result. Basically, my ISP – IAXN AS134316 does not has any route in it’s routing table for 45.120.248.51 and hence passing it to default route towards it’s upstream Airtel. BGP wise IAXN is not supposed to have any route belonging to IX peering IP anyways and that’s expected. Likely their router which peers with Extreme IX is different from the router which serves me and is possibly missing sharing of connected routes via IGP and hence the unexpected path. As soon as traffic hits Airtel router with a full routing table & no default route, it drops it.

In this setup, I cannot reach Spectra’s interface connected to the Extreme IX (45.120.248.51) directly if I try to send packets to it. But I do know from the first trace that it comes in middle when I try to send packets to 180.151.151.151. This option can be used where packets can be sent with incremental TTL and latency can be measured and even graphed. This concept can be used even if there’s a use of private IPs before the destination.

So this goes to my Probe config

+ TraceroutePing

binary = /usr/bin/traceroute # mandatory
binaryv6 = /usr/bin/traceroute6
forks = 5
offset = 50%
step = 300
timeout = 15

and this goes to my Target’s config

++SpectraExtremeIXInterface
probe = TraceroutePing
menu = Spectra via Extreme IX
title = Spectra via Extreme IX
host = 45.120.248.51
desthost = 180.151.151.151
maxttl = 15
minttl = 5
pings = 5
wait = 3

How it works?

A reminder on working on traceroute!

Remember the concept of TTL in IP routing. TTL is time to live and basically whenever the router passes the packets, it decreases TTL by 1 and when TTL reaches 0, the router just drops it. This ensures loops aren’t as dangerous in layer 3 as we see in layer 2. Now when a router drops packets with TTL 0, it replies back to the source saying “TTL exceeded” and the reply packets have the router’s source IP address. That way traceroute can send 1st packet with TTL 1, 1st router in the chain gets it, reduces TTL by 1 and (now that TTL is 0) drops it with a reply from its source IP. Next, another packet is sent with TTL 2 and so on.

Note: Thanks to networking folks from OVH Cloud who replied me with this probe on Twitter. It wasn’t what I was looking for but quite fascinating and useful!
Time to go back into the routing world! 🙂

29 Jan

Amazon India peering check

And here goes first blog post of 2018. Last few months went busy with some major changes in personal life. 🙂

I looked into Amazon’s India connectivity with various ASNs tonight. Here’s how it looks like. (Note: Jump to bottom most to skip traces and look at the summary data).
 
Amazon India to Vodafone India

traceroute to 118.185.107.1 (118.185.107.1), 30 hops max, 60 byte packets
 1 ec2-52-66-0-128.ap-south-1.compute.amazonaws.com (52.66.0.128) 21.861 ms ec2-52-66-0-134.ap-south-1.compute.amazonaws.com (52.66.0.134) 19.244 ms 19.233 ms
 2 100.64.2.200 (100.64.2.200) 14.789 ms 100.64.0.200 (100.64.0.200) 20.731 ms 100.64.3.12 (100.64.3.12) 13.187 ms
 3 100.64.0.193 (100.64.0.193) 14.418 ms 100.64.3.69 (100.64.3.69) 15.469 ms 100.64.3.67 (100.64.3.67) 15.946 ms
 4 100.64.16.67 (100.64.16.67) 0.343 ms 100.64.17.165 (100.64.17.165) 0.312 ms 100.64.17.199 (100.64.17.199) 0.313 ms
 5 52.95.67.213 (52.95.67.213) 1.942 ms 52.95.67.209 (52.95.67.209) 1.967 ms 52.95.67.213 (52.95.67.213) 1.935 ms
 6 52.95.66.218 (52.95.66.218) 4.998 ms 4.694 ms 52.95.66.130 (52.95.66.130) 4.650 ms
 7 52.95.66.67 (52.95.66.67) 1.752 ms 52.95.66.89 (52.95.66.89) 1.850 ms 1.806 ms
 8 52.95.217.183 (52.95.217.183) 3.111 ms 3.102 ms 3.088 ms <- Amazon India
 9 182.19.106.204 (182.19.106.204) 3.426 ms 4.547 ms 4.537 ms <- Vodafone India
10 118.185.107.1 (118.185.107.1) 2.035 ms 2.059 ms 2.039 ms

 
Amazon India to IDEA

traceroute to 223.196.83.1 (223.196.83.1), 30 hops max, 60 byte packets
 1 ec2-52-66-0-128.ap-south-1.compute.amazonaws.com (52.66.0.128) 16.133 ms ec2-52-66-0-132.ap-south-1.compute.amazonaws.com (52.66.0.132) 14.232 ms ec2-52-66-0-130.ap-south-1.compute.amazonaws.com (52.66.0.130) 21.267 ms
 2 100.64.3.10 (100.64.3.10) 16.418 ms 100.64.1.76 (100.64.1.76) 20.674 ms 100.64.1.206 (100.64.1.206) 26.416 ms
 3 100.64.3.129 (100.64.3.129) 18.727 ms 100.64.3.135 (100.64.3.135) 13.790 ms 100.64.3.133 (100.64.3.133) 20.787 ms
 4 100.64.16.101 (100.64.16.101) 0.323 ms 100.64.16.195 (100.64.16.195) 0.296 ms 100.64.16.135 (100.64.16.135) 2.358 ms
 5 52.95.67.213 (52.95.67.213) 1.879 ms 2.452 ms 2.465 ms
 6 52.95.66.174 (52.95.66.174) 2.717 ms 52.95.66.130 (52.95.66.130) 8.568 ms 52.95.66.64 (52.95.66.64) 6.004 ms
 7 52.95.66.183 (52.95.66.183) 4.361 ms 52.95.66.73 (52.95.66.73) 11.474 ms 52.95.66.51 (52.95.66.51) 11.414 ms
 8 52.95.217.201 (52.95.217.201) 3.585 ms 3.627 ms 3.420 ms
 9 223.196.6.237 (223.196.6.237) 3.704 ms 3.832 ms 3.826 ms
10 223.196.15.26 (223.196.15.26) 6.155 ms 223.196.2.141 (223.196.2.141) 8.472 ms *

 
Amazon India to Reliance Communications

traceroute to 115.252.64.1 (115.252.64.1), 30 hops max, 60 byte packets
 1 ec2-52-66-0-132.ap-south-1.compute.amazonaws.com (52.66.0.132) 18.567 ms ec2-52-66-0-134.ap-south-1.compute.amazonaws.com (52.66.0.134) 19.024 ms 19.020 ms
 2 100.64.0.72 (100.64.0.72) 22.429 ms 100.64.0.200 (100.64.0.200) 19.483 ms 100.64.2.142 (100.64.2.142) 18.679 ms
 3 100.64.1.67 (100.64.1.67) 11.717 ms 100.64.0.7 (100.64.0.7) 30.194 ms 100.64.2.195 (100.64.2.195) 11.700 ms
 4 100.64.16.195 (100.64.16.195) 0.353 ms 100.64.16.67 (100.64.16.67) 0.398 ms 100.64.17.163 (100.64.17.163) 0.400 ms
 5 52.95.67.209 (52.95.67.209) 1.847 ms 1.879 ms 1.891 ms
 6 52.95.66.108 (52.95.66.108) 5.567 ms 52.95.67.108 (52.95.67.108) 11.119 ms 52.95.66.174 (52.95.66.174) 9.029 ms
 7 52.95.66.141 (52.95.66.141) 2.938 ms 52.95.67.99 (52.95.67.99) 1.755 ms 52.95.67.165 (52.95.67.165) 1.755 ms
 8 54.239.43.171 (54.239.43.171) 18.605 ms 54.239.44.63 (54.239.44.63) 18.034 ms 54.239.43.171 (54.239.43.171) 18.522 ms
 9 52.93.19.126 (52.93.19.126) 63.893 ms 52.93.19.82 (52.93.19.82) 23.508 ms 52.93.19.62 (52.93.19.62) 20.812 ms
10 52.93.19.139 (52.93.19.139) 19.302 ms 52.93.19.133 (52.93.19.133) 18.600 ms 52.93.19.25 (52.93.19.25) 18.365 ms
11 115.110.161.61.static.vsnl.net.in (115.110.161.61) 17.966 ms 18.201 ms 115.110.161.65.static.vsnl.net.in (115.110.161.65) 17.948 ms
12 121.244.23.6.STATIC.Chennai.vsnl.net.in (121.244.23.6) 18.391 ms * *
13 115.255.253.69 (115.255.253.69) 27.234 ms 27.455 ms 27.652 ms
14 115.255.28.129 (115.255.28.129) 27.836 ms 121.244.23.6.STATIC.Chennai.vsnl.net.in (121.244.23.6) 18.906 ms 18.809 ms
15 115.255.232.1 (115.255.232.1) 27.524 ms 115.255.253.69 (115.255.253.69) 27.971 ms 115.255.232.1 (115.255.232.1) 27.777 ms
16 220.227.241.217 (220.227.241.217) 27.841 ms * 27.886 ms
17 115.255.232.1 (115.255.232.1) 27.628 ms 27.920 ms 27.965 ms
18 220.227.241.217 (220.227.241.217) 29.835 ms 220.224.230.177 (220.224.230.177) 28.402 ms *

 
Amazon India to Powergrid Corp

traceroute to 43.227.132.1 (43.227.132.1), 30 hops max, 60 byte packets
 1 ec2-52-66-0-132.ap-south-1.compute.amazonaws.com (52.66.0.132) 15.971 ms ec2-52-66-0-128.ap-south-1.compute.amazonaws.com (52.66.0.128) 11.558 ms ec2-52-66-0-134.ap-south-1.compute.amazonaws.com (52.66.0.134) 19.813 ms
 2 100.64.0.14 (100.64.0.14) 18.356 ms 100.64.2.200 (100.64.2.200) 15.390 ms 15.390 ms
 3 100.64.2.1 (100.64.2.1) 21.122 ms 100.64.3.3 (100.64.3.3) 19.208 ms 100.64.1.1 (100.64.1.1) 21.094 ms
 4 100.64.17.165 (100.64.17.165) 0.283 ms 100.64.16.39 (100.64.16.39) 0.323 ms 100.64.17.103 (100.64.17.103) 0.341 ms
 5 52.95.67.215 (52.95.67.215) 1.638 ms 52.95.67.211 (52.95.67.211) 0.702 ms 52.95.67.215 (52.95.67.215) 0.749 ms
 6 52.95.67.64 (52.95.67.64) 1.103 ms 52.95.67.86 (52.95.67.86) 4.012 ms 3.986 ms
 7 52.95.67.51 (52.95.67.51) 0.599 ms 52.95.67.29 (52.95.67.29) 0.662 ms 52.95.67.51 (52.95.67.51) 0.651 ms
 8 52.95.219.49 (52.95.219.49) 7.935 ms 8.111 ms 8.675 ms
 9 kalwa-edge-177.230.218.103.powergrid.in (103.218.230.177) 1.452 ms 1.641 ms 1.169 ms
10 43.227.132.65 (43.227.132.65) 49.309 ms 49.233 ms 49.296 ms
11 43.227.132.1 (43.227.132.1) 58.909 ms 58.975 ms 58.893 ms

 
Amazon India to BSNL

traceroute to 218.248.235.130 (218.248.235.130), 30 hops max, 60 byte packets
 1 ec2-52-66-0-128.ap-south-1.compute.amazonaws.com (52.66.0.128) 15.199 ms 15.173 ms ec2-52-66-0-130.ap-south-1.compute.amazonaws.com (52.66.0.130) 16.306 ms
 2 100.64.2.140 (100.64.2.140) 18.831 ms 100.64.2.202 (100.64.2.202) 18.159 ms 100.64.2.78 (100.64.2.78) 15.493 ms
 3 100.64.1.1 (100.64.1.1) 16.829 ms 100.64.1.129 (100.64.1.129) 16.823 ms 100.64.2.193 (100.64.2.193) 16.813 ms
 4 100.64.16.193 (100.64.16.193) 0.403 ms 100.64.17.133 (100.64.17.133) 0.290 ms 100.64.17.99 (100.64.17.99) 0.289 ms
 5 52.95.67.215 (52.95.67.215) 0.803 ms 52.95.67.211 (52.95.67.211) 0.672 ms 0.702 ms
 6 52.95.66.130 (52.95.66.130) 7.382 ms 7.107 ms 52.95.67.174 (52.95.67.174) 2.292 ms
 7 52.95.66.179 (52.95.66.179) 1.819 ms 52.95.67.91 (52.95.67.91) 0.658 ms 52.95.66.91 (52.95.66.91) 1.798 ms
 8 52.95.217.42 (52.95.217.42) 0.534 ms 0.505 ms 52.95.217.38 (52.95.217.38) 2.010 ms
 9 182.79.178.199 (182.79.178.199) 1.938 ms 182.79.178.63 (182.79.178.63) 1.936 ms 182.79.178.201 (182.79.178.201) 1.926 ms
10 * * aes-static-042.105.144.59.airtel.in (59.144.105.42) 3.179 ms
11 218.248.235.157 (218.248.235.157) 3.106 ms 3.230 ms *
12 218.248.235.129 (218.248.235.129) 40.928 ms 40.433 ms 40.853 ms
13 218.248.235.130 (218.248.235.130) 40.307 ms 40.384 ms 40.280 ms

 
Trace from Amazon India to Google’s anycasted 8.8.8.8:

traceroute -A 8.8.8.8
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
1 ec2-52-66-0-134.ap-south-1.compute.amazonaws.com (52.66.0.134) [AS38895/AS16509] 12.662 ms ec2-52-66-0-130.ap-south-1.compute.amazonaws.com (52.66.0.130) [AS38895/AS16509] 20.008 ms ec2-52-66-0-128.ap-south-1.compute.amazonaws.com (52.66.0.128) [AS38895/AS16509] 21.983 ms
2 100.64.0.142 (100.64.0.142) [AS22773] 15.525 ms 100.64.0.204 (100.64.0.204) [AS22773] 16.081 ms 100.64.1.206 (100.64.1.206) [AS22773] 19.696 ms
3 100.64.0.131 (100.64.0.131) [AS22773] 12.944 ms 12.893 ms 100.64.2.5 (100.64.2.5) [AS22773] 15.071 ms
4 100.64.16.103 (100.64.16.103) [AS22773] 0.318 ms 100.64.17.39 (100.64.17.39) [AS22773] 0.325 ms 100.64.17.69 (100.64.17.69) [AS22773] 0.291 ms
5 52.95.67.215 (52.95.67.215) [AS16509] 1.374 ms 5.725 ms 4.294 ms
6 52.95.67.130 (52.95.67.130) [AS16509] 4.896 ms 52.95.67.86 (52.95.67.86) [AS16509] 2.021 ms 52.95.67.108 (52.95.67.108) [AS16509] 5.735 ms
7 52.95.67.111 (52.95.67.111) [AS16509] 0.705 ms 0.672 ms 0.670 ms
8 52.95.218.225 (52.95.218.225) [*] 0.542 ms 0.570 ms 0.505 ms
9 108.170.248.161 (108.170.248.161) [AS15169] 0.853 ms 108.170.248.193 (108.170.248.193) [AS15169] 0.804 ms 108.170.248.177 (108.170.248.177) [AS15169] 0.770 ms
10 108.170.234.9 (108.170.234.9) [AS15169] 1.449 ms 209.85.248.147 (209.85.248.147) [AS15169] 1.725 ms 1.728 ms
11 google-public-dns-a.google.com (8.8.8.8) [AS15169] 0.460 ms 0.744 ms 0.449 ms

 
Amazon India to Microsoft Azure India

traceroute to 52.172.52.79 (52.172.52.79), 30 hops max, 60 byte packets
 1 ec2-52-66-0-132.ap-south-1.compute.amazonaws.com (52.66.0.132) 11.434 ms ec2-52-66-0-134.ap-south-1.compute.amazonaws.com (52.66.0.134) 14.968 ms ec2-52-66-0-128.ap-south-1.compute.amazonaws.com (52.66.0.128) 14.694 ms
 2 100.64.2.8 (100.64.2.8) 15.301 ms 100.64.3.14 (100.64.3.14) 14.541 ms 100.64.2.10 (100.64.2.10) 15.289 ms
 3 100.64.0.131 (100.64.0.131) 19.954 ms 100.64.2.199 (100.64.2.199) 20.491 ms 100.64.1.135 (100.64.1.135) 20.473 ms
 4 100.64.16.67 (100.64.16.67) 6.650 ms 100.64.16.65 (100.64.16.65) 0.306 ms 100.64.16.133 (100.64.16.133) 0.307 ms
 5 52.95.67.213 (52.95.67.213) 1.917 ms 52.95.67.209 (52.95.67.209) 1.931 ms 1.980 ms
 6 52.95.66.130 (52.95.66.130) 3.015 ms 52.95.66.196 (52.95.66.196) 10.939 ms 52.95.66.86 (52.95.66.86) 11.644 ms
 7 52.95.66.91 (52.95.66.91) 1.802 ms 52.95.66.177 (52.95.66.177) 7.303 ms 52.95.66.199 (52.95.66.199) 3.435 ms
 8 52.95.218.61 (52.95.218.61) 16.785 ms 52.95.218.63 (52.95.218.63) 1.700 ms 1.674 ms
 9 ae0-0.bom02-96cbe-1b.ntwk.msn.net (104.44.226.17) 1.952 ms 1.897 ms ae14-0.bom30-96cbe-1b.ntwk.msn.net (198.206.164.159) 2.238 ms
10 ae14-0.bom30-96cbe-1b.ntwk.msn.net (198.206.164.159) 2.150 ms 2.172 ms ae5-0.maa30-96cbe-1a.ntwk.msn.net (104.44.226.241) 26.009 ms
11 ae5-0.maa30-96cbe-1a.ntwk.msn.net (104.44.226.241) 25.940 ms ae10-0.maa01-96cbe-1b.ntwk.msn.net (104.44.226.243) 27.591 ms 27.587 ms
12 ae10-0.maa01-96cbe-1b.ntwk.msn.net (104.44.226.243) 27.698 ms ae0-0.maa01-96cbe-1a.ntwk.msn.net (104.44.227.208) 28.090 ms *
13 * ae0-0.maa01-96cbe-1a.ntwk.msn.net (104.44.227.208) 27.682 ms *
14 * * *
15 * * *
16 * * *
17 * * *
18 *^C

 
Amazon India to Cloudflare India PoP

traceroute to amy.ns.cloudflare.com (173.245.58.101), 30 hops max, 60 byte packets
 1 ec2-52-66-0-130.ap-south-1.compute.amazonaws.com (52.66.0.130) [AS38895/AS16509] 13.912 ms ec2-52-66-0-134.ap-south-1.compute.amazonaws.com (52.66.0.134) [AS38895/AS16509] 15.167 ms 15.159 ms
 2 100.64.0.142 (100.64.0.142) [AS22773] 21.393 ms 100.64.3.72 (100.64.3.72) [AS22773] 16.098 ms 100.64.3.14 (100.64.3.14) [AS22773] 11.766 ms
 3 100.64.2.67 (100.64.2.67) [AS22773] 27.118 ms 100.64.2.131 (100.64.2.131) [AS22773] 27.097 ms 100.64.2.133 (100.64.2.133) [AS22773] 21.532 ms
 4 100.64.16.39 (100.64.16.39) [AS22773] 0.253 ms 100.64.17.193 (100.64.17.193) [AS22773] 0.256 ms 100.64.16.195 (100.64.16.195) [AS22773] 0.260 ms
 5 52.95.67.209 (52.95.67.209) [AS16509] 1.850 ms 1.846 ms 52.95.67.213 (52.95.67.213) [AS16509] 1.808 ms
 6 52.95.66.108 (52.95.66.108) [AS16509] 3.007 ms 52.95.66.174 (52.95.66.174) [AS16509] 13.312 ms 13.285 ms
 7 52.95.66.201 (52.95.66.201) [AS16509] 1.890 ms 52.95.66.135 (52.95.66.135) [AS16509] 2.571 ms 52.95.66.71 (52.95.66.71) [AS16509] 1.867 ms
 8 115.114.89.209.static-Mumbai.vsnl.net.in (115.114.89.209) [AS4755] 2.448 ms 115.114.89.189.static-Mumbai.vsnl.net.in (115.114.89.189) [AS4755] 1.984 ms 1.888 ms
 9 * * *
10 * 182.79.203.36 (182.79.203.36) [*] 2.459 ms *
11 182.79.223.54 (182.79.223.54) [*] 2.357 ms 2.368 ms 14.142.21.18.static-vsnl.net.in (14.142.21.18) [AS4755] 2.008 ms
12 amy.ns.cloudflare.com (173.245.58.101) [AS13335] 2.467 ms 182.79.203.44 (182.79.203.44) [*] 2.777 ms amy.ns.cloudflare.com (173.245.58.101) [AS13335] 2.445 ms

 
 
Some traces where traffic going from Amazon India is getting routed to Indian networks from outside:

traceroute to 125.18.237.1 (125.18.237.1), 30 hops max, 60 byte packets
 1 ec2-52-66-0-134.ap-south-1.compute.amazonaws.com (52.66.0.134) 18.252 ms ec2-52-66-0-130.ap-south-1.compute.amazonaws.com (52.66.0.130) 17.868 ms ec2-52-66-0-132.ap-south-1.compute.amazonaws.com (52.66.0.132) 20.634 ms
 2 100.64.3.76 (100.64.3.76) 15.640 ms 100.64.2.202 (100.64.2.202) 13.602 ms 100.64.0.74 (100.64.0.74) 14.663 ms
 3 100.64.3.197 (100.64.3.197) 2.152 ms 100.64.2.69 (100.64.2.69) 2.128 ms 100.64.3.69 (100.64.3.69) 2.134 ms
 4 100.64.17.37 (100.64.17.37) 0.337 ms 100.64.16.37 (100.64.16.37) 0.354 ms 100.64.17.129 (100.64.17.129) 0.293 ms
 5 52.95.67.213 (52.95.67.213) 1.902 ms 1.861 ms 52.95.67.209 (52.95.67.209) 1.867 ms
 6 52.95.66.64 (52.95.66.64) 5.317 ms 52.95.66.218 (52.95.66.218) 6.883 ms 52.95.66.196 (52.95.66.196) 9.687 ms
 7 52.95.66.203 (52.95.66.203) 1.817 ms 52.95.66.69 (52.95.66.69) 1.844 ms 52.95.66.137 (52.95.66.137) 1.792 ms
 8 115.114.89.121.static-Mumbai.vsnl.net.in (115.114.89.121) 1.745 ms 115.114.89.209.static-Mumbai.vsnl.net.in (115.114.89.209) 1.799 ms 115.114.89.121.static-Mumbai.vsnl.net.in (115.114.89.121) 2.034 ms
 9 * * *
10 ix-ae-4-2.tcore1.CXR-Chennai.as6453.net (180.87.36.9) 54.804 ms * *
11 if-ae-3-3.tcore2.CXR-Chennai.as6453.net (180.87.36.6) 228.066 ms ix-ae-4-2.tcore1.CXR-Chennai.as6453.net (180.87.36.9) 56.587 ms 53.271 ms
12 if-ae-3-3.tcore2.CXR-Chennai.as6453.net (180.87.36.6) 225.894 ms 226.883 ms 227.007 ms
13 if-ae-6-2.tcore2.SVW-Singapore.as6453.net (180.87.37.14) 226.616 ms 227.081 ms if-ae-10-2.tcore2.SVW-Singapore.as6453.net (180.87.37.65) 226.699 ms
14 if-ae-7-2.tcore2.LVW-Los-Angeles.as6453.net (180.87.15.26) 227.935 ms 225.266 ms 235.497 ms
15 xe-4-1-0.edge1.SanJose3.level3.net (4.68.62.105) 247.387 ms 257.588 ms 249.384 ms
16 ae-116-3502.edge3.London15.Level3.net (4.69.167.78) 241.053 ms 241.539 ms ae-115-3501.edge3.London15.Level3.net (4.69.167.74) 242.991 ms
17 ae-116-3502.edge3.London15.Level3.net (4.69.167.78) 240.407 ms ae-225-3601.edge3.London15.Level3.net (4.69.167.90) 243.525 ms ae-226-3602.edge3.London15.Level3.net (4.69.167.94) 241.484 ms
18 BHARTI-AIRT.edge3.London15.Level3.net (212.187.139.82) 244.356 ms 244.610 ms *
19 * * *
20 * * *
21 * * *
22 *^C

 
Summary of results

Network NameNetwork ASNDomestic Connectivity
Tata Communications4755Yes*
Airtel9498Yes*
Idea Cellular55644Yes
Reliance Communucations18101No
Aircel10201No
Powergrid Telecom132215Yes
Railtel24186Yes
BSNL9829No
NKN55824No
CtrlS18229No
Syscon Infoway45194No
Intech Online58678Yes
Charotar Broadband132933Yes
Ishan Tech45117Yes
Webwerks33480No
Blazenet17625Yes
Spectra10029Yes
Excitel Broadband133982Yes
Google15169Yes
Cloudflare13335No
Microsoft8075Yes

 
Misc points:

  1. *TCL and *Airtel seem to be IP transit provider of Amazon. For certain routes going outside India traffic seem to be going via Tata VSNL AS4755.
  2. Connectivity checked for certain random pools only and not for all announced routes for a large telco network.