[plug] Strange Traceroute networking issues
Tim
weirdit at gmail.com
Wed Dec 1 16:58:13 WST 2010
I have a box in South Africa that I need to work on, so have setup up
an OpenVPN between it and a box in Perth. Strangely though, it seems
to disconnect often and not reconnect for awhile, so while connected
today I started doing some traceroute stuff.
It appears that the public ip address I think the box has (i.e. the
address given if I use something like what is my ip, or get from my
ssh/openvpn logs on the server), isn't it's real public ip address.
I'm thinking some NAT might be happening, but don't know why NAT would
happen if they already have a public ip address.
If I login to the box over the VPN, I can then traceroute back to the
server, and discover the real public ip address. Traceroute from my
server to the box's real ip address works really nicely. Traceroute
from my server to the box's "fake" ipaddress just dies.
Both the paths to the "fake" ip and the real ip both look similar,
just one reachs the end the other doesn't. In the traceroute from the
remote box to my server, I can see where it appears to go through the
same networks as my reverse trace, but can't see where it could be
picking up the "fake" ip address from.
Anyone know what's happening and what I can do to try and get better vpn uptime?
Thanks
Tim
Traceroute from SA box to Perth Server. Reveals true ip address of the
connection.
$ tracepath purewhite.id.au
1: serve.dummy.porta.siemens.net (10.0.0.84) 0.396ms pmtu 1500
1: sx76x-danube.dummy.porta.siemens.net (10.0.0.2) 1.061ms
1: sx76x-danube.dummy.porta.siemens.net (10.0.0.2) 1.068ms
2: sx76x-danube.dummy.porta.siemens.net (10.0.0.2) 1.049ms pmtu 1492
2: dsl-242-220-01.telkomadsl.co.za (41.242.220.1) 386.301ms
3: 196.43.33.81 (196.43.33.81) 397.059ms asymm 6
4: 196.43.33.81 (196.43.33.81) 369.224ms asymm 6
5: 196.43.10.130 (196.43.10.130) 431.237ms asymm 9
6: 196.43.33.5 (196.43.33.5) 448.048ms asymm 7
7: hkg-ip-dir-hongkong-pos-4-0-3.telkom-ipnet.co.za (196.43.18.214)
683.656ms asymm 9
8: ge13-2.br01.hkg04.pccwbtn.net (63.218.115.109) 648.144ms asymm 9
9: singtel.ge5-13.br01.hkg04.pccwbtn.net (63.218.115.50) 654.149ms asymm 10
10: 203.208.152.130 (203.208.152.130) 714.681ms asymm 11
11: so-4-3-0-0.sngtp-ar6.ix.singtel.com (203.208.151.69) 667.718ms asymm 12
12: 203.208.152.210 (203.208.152.210) 649.834ms asymm 13
13: GigabitEthernet2-1-1.sngtp-ar4.ix.singtel.com (203.208.183.122) 654.740ms
14: 203.208.148.94 (203.208.148.94) 749.856ms
15: no reply
16: no reply
17: 202.139.129.18 (202.139.129.18) 743.455ms asymm 16
18: 203.24.54.53 (203.24.54.53) 794.540ms asymm 17
19: 202-74-162-14.static.globaldial.com (202.74.162.14) 793.338ms asymm 17
20: no reply
...
Tracepath from Perth server to revealed ip address above works nicely.
$ tracepath 41.242.220.1
1: purewhite.id.au (175.41.45.10) 0.111ms pmtu 1500
1: talkietoaster.labyrinthdata.net.au (175.41.45.1) 0.851ms
1: talkietoaster.labyrinthdata.net.au (175.41.45.1) 0.820ms
2: 202-74-162-13.static.globaldial.com (202.74.162.13) 1.725ms
3: se0.spherion.global.net.au (203.24.54.50) 4.242ms
4: v13.dist.global.net.au (203.24.54.54) 10.134ms asymm 3
5: 202.139.129.17 (202.139.129.17) 8.964ms asymm 4
6: ge-1-1-4-0.sngtp-dr2.ix.singtel.com (203.208.183.73) 105.761ms asymm 9
7: 203.208.152.205 (203.208.152.205) 98.971ms asymm 10
8: so-3-0-3-0.hkgcw-cr3.ix.singtel.com (203.208.154.38) 106.927ms asymm 10
9: 203.208.152.194 (203.208.152.194) 256.262ms asymm 13
10: no reply
11: 203.131.243.18 (203.131.243.18) 114.622ms asymm 13
12: rrba-ip-cr-1-ge-0-0-2.telkom-ipnet.co.za (196.43.9.122) 100.337ms asymm 14
13: 196.43.33.10 (196.43.33.10) 289.577ms asymm 15
14: 196.43.10.129 (196.43.10.129) 263.919ms asymm 16
15: 196.43.10.89 (196.43.10.89) 295.849ms reached
Resume: pmtu 1500 hops 15 back 235
Tracepath from Perth server to IP address connections from SA come in from.
$ tracepath 41.242.237.145
1: tahn.purewhite.id.au (175.41.45.10) 0.084ms pmtu 1500
1: talkietoaster.labyrinthdata.net.au (175.41.45.1) 0.803ms
1: talkietoaster.labyrinthdata.net.au (175.41.45.1) 0.816ms
2: 202-74-162-13.static.globaldial.com (202.74.162.13) 1.806ms
3: se0.spherion.global.net.au (203.24.54.50) 3.912ms
4: v13.dist.global.net.au (203.24.54.54) 7.547ms asymm 3
5: 202.139.129.17 (202.139.129.17) 4.870ms asymm 4
6: ge-1-1-4-0.sngtp-dr2.ix.singtel.com (203.208.183.73) 105.624ms asymm 9
7: 203.208.152.213 (203.208.152.213) 134.405ms asymm 10
8: so-3-0-1-0.hkgcw-cr3.ix.singtel.com (203.208.151.82) 174.086ms asymm 11
9: 203.208.152.194 (203.208.152.194) 258.091ms asymm 13
10: no reply
11: 203.131.243.18 (203.131.243.18) 114.179ms asymm 13
12: 203.131.243.18 (203.131.243.18) 115.526ms asymm 13
13: 196.43.33.10 (196.43.33.10) 268.348ms asymm 15
14: 196.43.33.10 (196.43.33.10) 253.590ms asymm 15
15: 196.43.10.89 (196.43.10.89) 258.808ms asymm 21
16: 196.43.10.89 (196.43.10.89) 258.795ms asymm 21
17: 196.43.10.89 (196.43.10.89) 280.708ms asymm 21
18: no reply
19: 196.43.10.89 (196.43.10.89) 326.634ms pmtu 1492
19: no reply
--
Timothy White - Somewhere in Australia
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