Hi all,
I did a traceroute to the HK PoP (216.218.221.6) from an Airtel (an Indian ISP). Following are my results:
% traceroute -I 216.218.221.6
traceroute to 216.218.221.6 (216.218.221.6), 64 hops max, 72 byte packets
1 * * *
2 ABTS-North-Static-246.220.160.122.airtelbroadband.in (122.160.220.246) 31.533 ms 42.310 ms 32.772 ms
3 rasBTNLDel-static-174.215.56.202.mantraonline.com (202.56.215.174) 33.040 ms 32.200 ms 35.445 ms
4 125.19.22.145 (125.19.22.145) 39.870 ms 31.754 ms 35.116 ms
5 59.145.6.62 (59.145.6.62) 84.515 ms 84.201 ms 84.951 ms
6 if-7-0-0.core1.S2E-Singapore.as6453.net (216.6.91.73) 113.055 ms 111.871 ms 109.877 ms
7 Vlan1124.icore1.S9U-Singapore.as6453.net (116.0.83.17) 126.084 ms 130.112 ms 126.356 ms
8 Vlan32.icore1.HK2-HongKong.as6453.net (116.0.83.2) 159.605 ms 150.740 ms 148.081 ms
9 hurricaneelectric-RGE.hkix.net (202.40.161.158) 321.999 ms 324.960 ms 324.916 ms
10 tserv20.hkg1.ipv6.he.net (216.218.221.6) 304.791 ms 304.445 ms 305.538 ms
Note the 150ms latency between 116.0.83.2 and 202.40.161.158, from their names it seems both of these boxes are located in HK. Then why is this latency of 150ms ?
I'm at present using London PoP (216.66.80.26) and a traceroute to that is given below:
% traceroute -I 216.66.80.26
traceroute to 216.66.80.26 (216.66.80.26), 64 hops max, 72 byte packets
1 * * *
2 ABTS-North-Static-246.220.160.122.airtelbroadband.in (122.160.220.246) 32.918 ms 33.959 ms 34.769 ms
3 ABTS-North-Static-158.230.160.122.airtelbroadband.in (122.160.230.158) 34.723 ms 32.785 ms 36.175 ms
4 125.19.22.145 (125.19.22.145) 34.925 ms 33.071 ms 30.976 ms
5 59.145.6.57 (59.145.6.57) 88.930 ms 90.327 ms 89.109 ms
6 so-2-3-0-zcr1.lnt.cw.net (166.63.222.53) 247.870 ms 250.581 ms 263.865 ms
7 so-3-0-0-bcr1.lnd.cw.net (166.63.163.221) 322.265 ms 248.611 ms 250.025 ms
8 xe-0-3-0.xcr1.lnd.cw.net (195.2.25.1) 249.050 ms
xe-5-0-0-xcr1.lnd.cw.net (195.2.25.121) 245.164 ms 250.088 ms
9 xe-11-1-0.xcr1.lsw.cw.net (195.2.25.53) 254.536 ms
xe-11-2-0.xcr1.lsw.cw.net (195.2.25.57) 248.405 ms
xe-11-1-0.xcr1.lsw.cw.net (195.2.25.53) 251.785 ms
10 linx.he.net (195.66.224.21) 368.798 ms 371.511 ms 368.756 ms
11 tserv5.lon1.ipv6.he.net (216.66.80.26) 367.138 ms 365.565 ms 368.852 ms
Before the recent undersea cable cut, it used to be reachable in 250ms. I'm wondering if after the repair of undersea cable, HK PoP is going to be reachable any faster than London's PoP ?
Thanks
Ashish SHUKLA
Form the HE point of view (http://lg.he.net/cgi-bin/index.cgi)
Tracing the route to IP node ABTS-North-Static-246.220.160.122.airtelbroadband.in [122.160.220.246] from 1 to 30 hops
1 179 ms 175 ms 175 ms v1026.core1.sjc1.he.net [72.52.92.173]
2 173 ms 176 ms 176 ms 10gigabitethernet2-1.core1.sjc2.he.net [72.52.92.118]
3 174 ms 174 ms 174 ms ge13-1.br02.sjo01.pccwbtn.net [206.223.116.48]
4 454 ms 450 ms 451 ms bharti.pos11-0.cr02.sin02.pccwbtn.net [63.218.165.214]
5 502 ms 503 ms 502 ms 203.101.100.186
6 508 ms 508 ms 508 ms 125.19.22.146
7 505 ms 503 ms 504 ms ABTS-North-Static-246.220.160.122.airtelbroadband.in [122.160.220.246]
QuoteThen why is this latency of 150ms ?
Becuose of different return routing paths.
So the peering with as6453.net is working in one way only. HE is returning the traffice to us via USA.
Probably it could be improve by HE.
PJ
EDIT:
also the frankfurt tserver is closest to u now: should be 255ms (216.66.80.30), hkg might be after a fix :P
Quote from: piojan on January 11, 2009, 07:48:26 AM
also the frankfurt tserver is closest to u now: should be 255ms (216.66.80.30), hkg might be after a fix :P
Thanks for the reply, but I didn't get why is there 150ms of latency between two routers placed in the same DC (or the same country) ? I agree with you about one way route between India and Hong Kong.
Any guesses which one will be faster if Hong Kong router gets 2-way peering and undersea cable gets fixed ? I guess then it will be Hong Kong, London, Frankfurt (in order of increasing RTTs).
It's because your ISP (or their upstreams) does not advertise the return route to the HKIX exchange in Hong Kong.
By going to Hurricane Electric's looking glass at http://lg.he.net and selecting command "BGP", entering that IP where it says "Argument", selecting the Hong Kong router, we see the following output:
Number of BGP Routes matching display condition : 1
Status codes: s suppressed, d damped, h history, * valid, > best, i internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*>i 122.160.220.0/24 206.223.116.48 1 100 0 3491 9498 24560 i
Last update to IP routing table: 2h54m55s, 1 path(s) installed:
Hurricane sees this route from AS3491 (PCCW BTN).
A further traceroute from Hong Kong to the IP reveals that it goes back to the US, confirming that PCCW does not annouce this route at HKIX in Hong Kong.
Okay. I didn't noticed this fact earlier.
Thanks everyone for the replies.