Wednesday, September 16, 2026

traceroutes just for general interest

I had asked an LLM about the network backhaul used by our ISPs like Airtel, BSNL etc, and was told that while there was no publicly available information about the actual specifications of their backhaul, a traceroute might give more information. Some traceroutes to google.com and nebula.tv from BSNLindicated that they terminated at their Points of Presence - POPs in Chennai - nebula.tv via Cloudflare. With Airtel, google.com seems to go to a Mumbai POP - bom.

traceroute to google.com (142.250.183.174), 64 hops max, 40 byte packets
 1  10.219.86.239 (10.219.86.239)  3.068 ms  3.368 ms  3.003 ms
 2  * * *
 3  192.168.116.2 (192.168.116.2)  64.774 ms  35.220 ms  29.967 ms
 4  * * *
 5  * * *
 6  125.21.99.61 (125.21.99.61)  36.796 ms
    dsl-ncr-dynamic-013.32.23.125.airtelbroadband.in (125.23.32.13)  28.051 ms  44.851 ms
 7  182.79.177.69 (182.79.177.69)  40.855 ms
    116.119.68.247 (116.119.68.247)  47.689 ms
    116.119.161.183 (116.119.161.183)  40.998 ms
 8  * 142.250.169.206 (142.250.169.206)  58.361 ms *
 9  142.250.230.197 (142.250.230.197)  158.451 ms *
    64.233.174.17 (64.233.174.17)  289.370 ms
10  142.251.55.67 (142.251.55.67)  38.116 ms
    142.251.55.230 (142.251.55.230)  233.997 ms
    142.251.55.42 (142.251.55.42)  37.590 ms
11  142.251.55.65 (142.251.55.65)  38.276 ms
    142.251.55.67 (142.251.55.67)  41.114 ms
    172.253.71.132 (172.253.71.132)  37.117 ms
12  bom07s32-in-f14.1e100.net (142.250.183.174)  58.148 ms  35.764 ms
    142.250.62.67 (142.250.62.67)  42.145 ms

Then, a couple of traceroutes to a US server, from BSNL fiber to home network done from a Windows machine

tracert ourdomain.org

Tracing route to ourdomain [redacted]
over a maximum of 30 hops:

  1     1 ms    <1 ms    <1 ms  192.168.1.1
  2     2 ms     4 ms     2 ms  117.192.80.1
  3     4 ms     3 ms     3 ms  10.219.29.194
  4     *        *        *     Request timed out.
  5     *        *        *     Request timed out.
  6    13 ms    13 ms    13 ms  10.200.120.225
  7     *        *        *     Request timed out.
  8    15 ms    14 ms    15 ms  115.110.161.189.static.vsnl.net.in [115.110.161.189]
  9    37 ms    50 ms    37 ms  172.25.199.34
 10    37 ms    36 ms    38 ms  172.28.124.134
 11    39 ms    36 ms    75 ms  172.25.138.206
 12     *        *        *     Request timed out.
 13     *        *        *     Request timed out.
 14     *        *        *     Request timed out.
 15     *      278 ms     *     if-bundle-12-2.qcore2.pvu-paris.as6453.net [80.231.245.13]
 16   272 ms   271 ms     *     ae0.cr2.dfw7.us.zip.zayo.com [64.125.20.63]
 17   272 ms   272 ms   293 ms  ae1.cr2.chd4.us.zip.zayo.com [64.125.25.76]
 18   257 ms     *      353 ms  ae9.cr1.phx4.us.zip.zayo.com [64.125.27.186]
 19     *        *        *     Request timed out.
 20   274 ms   272 ms   273 ms  64.125.199.194.IDIA-409280-003-ZYO.zip.zayo.com [64.125.199.194]
 21   241 ms   246 ms   241 ms  core1-edge2-lag1.phx1.codero.com [216.55.160.6]
 22   254 ms   251 ms   251 ms  216-55-160-81.dedicated.codero.net [216.55.160.81]
(and the next hop was our server in Phoenix.)

So apparently BSNL routed this request via Tata Communications (vsnl), via Paris interconnect to Zayo, and there to Phoenix. Of course, routes would vary from time to time, too.

Trying from a Mac via Airtel 5G network,

traceroute ourdomain.org
traceroute to ourdomain.org (redacted), 64 hops max, 40 byte packets
 1  10.219.86.239 (10.219.86.239)  3.615 ms  2.808 ms  2.575 ms
 2  * * *
 3  192.168.116.2 (192.168.116.2)  28.903 ms  32.648 ms  70.657 ms
 4  * 192.168.116.49 (192.168.116.49)  42.654 ms  33.930 ms
 5  * * *
 6  dsl-ncr-dynamic-013.32.23.125.airtelbroadband.in (125.23.32.13)  49.859 ms
    125.21.99.61 (125.21.99.61)  60.570 ms
    dsl-ncr-dynamic-013.32.23.125.airtelbroadband.in (125.23.32.13)  27.138 ms
 7  116.119.167.20 (116.119.167.20)  249.939 ms
    116.119.167.119 (116.119.167.119)  339.057 ms
    116.119.167.20 (116.119.167.20)  251.139 ms
 8  * * *
 9  be3271.ccr41.lax01.atlas.cogentco.com (154.54.42.101)  348.294 ms  258.764 ms  332.531 ms
10  be2932.ccr32.phx01.atlas.cogentco.com (154.54.45.161)  284.207 ms
    be2931.ccr31.phx01.atlas.cogentco.com (154.54.44.85)  256.272 ms  418.788 ms
11  be3452.rcr21.phx02.atlas.cogentco.com (66.28.4.242)  308.459 ms
    be3451.rcr21.phx02.atlas.cogentco.com (66.28.4.26)  432.845 ms  248.367 ms
12  38.122.88.107 (38.122.88.107)  253.042 ms  252.078 ms  246.671 ms
13  core1-edge1-lag1.phx1.codero.com (216.55.160.4)  273.957 ms  253.373 ms  259.721 ms
14  59-160-55-216.dedicated.codero.net (216.55.160.59)  303.754 ms  307.035 ms
    216-55-160-71.dedicated.codero.net (216.55.160.71)  259.048 ms
15  ourdomain.org (redacted)  444.128 ms  405.611 ms  409.528 ms

In this case, the route seemed to be within Airtel (Bharti Telecom) till the 8th hop, and then directly LA and then Phoenix.

 

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