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I am based in India and I am using rackspace virtual server in Hong Kong. Also, I am communicating to a external website hosted in Hong Kong. So, there are three computer end-points to consider as follows:
1) A - My home pc in India 2) B - Rackspace virtual server in Honk Kong 3) C - External server in Hong Kong.
Now, the ping time from B to C is roughly 2-3 ms, which is to be expected as they are fairly close geographically to each other. But ping time from A to B is roughly 300 ms and ping time from A to C is roughly 150 ms. Since both B and C are located are roughly equal distance to A, why is there so much difference in ping time?
Traceert(partial) from A to C
4 38 ms 36 ms 37 ms 125.18.13.137
5 121 ms 123 ms 124 ms 182.79.252.6
6 125 ms 124 ms 130 ms vlan65.te13-2.br01.sin02.pccwbtn.net [63.218.229.81]
7 127 ms 127 ms 126 ms att.tenge13-4.br01.hkg04.pccwbtn.net [63.218.2.122]
8 157 ms 155 ms 156 ms 165.87.76.214
9 128 ms 129 ms 129 ms 32.114.131.30
Tracert(partial) from A to B
4 39 ms 36 ms 37 ms 125.18.13.137
5 168 ms 168 ms 168 ms 182.79.222.17
6 184 ms 172 ms 179 ms 40ge1-3.core1.lon2.he.net [195.66.224.21]
7 174 ms 172 ms 172 ms 100ge5-1.core1.par2.he.net [184.105.223.254]
8 272 ms 273 ms 272 ms 10ge3-1.core1.sin1.he.net [184.105.222.114]
9 277 ms 276 ms 273 ms 10ge6-1.core1.hkg1.he.net [184.105.223.189]
10 253 ms 254 ms 254 ms agc1-10G.hkix.net [123.255.90.175]
11 266 ms 269 ms 269 ms xe0-3-1.gw1.hkg3.asianetcom.net [61.14.157.81]
12 255 ms 255 ms 254 ms 61.8.56.3
13 255 ms 256 ms 255 ms edge4.hkg30-core1a.hkg1.rackspace.net [120.136.47.136]
14 274 ms 275 ms 276 ms dcpe1-core1b.hkg1.rackspace.net [120.136.47.173]
15 256 ms 257 ms 255 ms 119.9.64.67
(I have removed the first 3 and last line from the tracert output to remove personal infromation)
lonstud
Posted 2015-08-18T03:56:28.607
Reputation: 83
There is no way to answer this without traceroute details... For example A to B might take a detour through Ireland. This can't be answered without more detail. – Tyson – 2015-08-18T04:00:45.133
@Tyson, I have posted the tracert results. Probably a rookie question, but shouldn't ping take the shortest path. – lonstud – 2015-08-18T04:12:52.820
1That's relative... Let's say rackspaces uses backbone providers A, C, D. Let's say you other server only has access to the backbone provider B. The best route may vary drastically. As you can see from your own traceroutes. That's way oversimplified but it shows you why. – Tyson – 2015-08-18T04:16:00.110
Your traceroute data shows exactly why. 2x the hops (5 vs 11) ~= 2x the delay (150 vs 300). Why would you expect it to be significantly less than that from A to B? – krowe – 2015-08-18T04:20:00.990
@krowe, both B and C are located geographically close to each other in Hong Kong as can be verified from ping times from B to C. Hence, I expected time from A to B and A to C to be fairly close to each other. May be I do not understand very well the concept of how ping works. I'll research further into it. – lonstud – 2015-08-18T04:22:22.853
1@amitchaudhary Geographic proximity is only part of the equation. Routing path is the other part of the equation, so you have your answer. They are on different networks. – Paul – 2015-08-18T04:39:45.783
1It's not how ping works that your not understanding. It's how the internet is routed that comes into play. All the Internet backbone providers have agreements to route each other's traffic... But it goes further than that, for example they prefer to use there own fiber first, after that they may prefer one over another. The route from A to B and A to C can be very different. And the route back may or may not be the same or similar. You have no control over these routes. – Tyson – 2015-08-18T04:45:41.663
2It looks like A to B is being routed from India through London, Paris, Singapore and then to Hong Kong. That explains the delay. There's not much you can do Rio change this either as it has to do with routing tables not under your control. – heavyd – 2015-08-18T06:40:28.090
BTW, a traceroute of B to C and C to B may be interesting as well (and may not be the same path) – heavyd – 2015-08-18T06:43:01.263
Thank you @Tyson heavyd Paul for explaining about the routing path. That clarifies my doubt. – lonstud – 2015-08-18T07:42:56.240
The only thing in my mind like what @heavyd said, It's to hard to compare pings, I made a simuler test to my server and have different result too check this article
– Narzan Q. – 2015-08-18T08:28:09.503