This is a discussion on interpretation of output from traceroute - TCP-IP ; Folk, A diagram of my network is visible. http://carnot.yi.org/Network.jpg I aim to have SMTP from Cantor, via the tunnel to Joule and thence to shawmail.gv.shawcable.net. On Joule, this seems reasonable. joule:~# traceroute -p 25 shawmail.gv.shawcable.net traceroute to shawmail.gv.shawcable.net (24.71.223.43), 30 ...
Folk,
A diagram of my network is visible.
http://carnot.yi.org/Network.jpg
I aim to have SMTP from Cantor, via the tunnel to Joule
and thence to shawmail.gv.shawcable.net.
On Joule, this seems reasonable.
joule:~# traceroute -p 25 shawmail.gv.shawcable.net
traceroute to shawmail.gv.shawcable.net (24.71.223.43), 30 hops max,
40 byte packets
1 24.108.32.1 (24.108.32.1) 11.480 ms 11.465 ms 11.500 ms
2 rd1cv-ge3-3-4.gv.shawcable.net (64.59.166.162) 13.077 ms 13.116
ms 13.079 ms
3 rc2bb-pos0-1-5-0.vc.shawcable.net (66.163.77.185) 14.938 ms
14.373 ms 14.390 ms
4 rc2wh-tge0-15-1-0.vc.shawcable.net (66.163.69.121) 14.914 ms
15.063 ms 15.031 ms
5 rc1so-pos1-0-0.cg.shawcable.net (66.163.77.198) 28.026 ms 28.718
ms 28.759 ms
6 * * *
...
30 * * *
On Dalton, this puzzles me.
dalton:~# traceroute -p 25 shawmail.gv.shawcable.net
traceroute to shawmail.gv.shawcable.net (64.59.128.135), 30 hops max,
40 byte pa
ckets
1 joule.petershouse.invalid (10.4.0.1) 17.036 ms 15.609 ms 16.434
ms
2 joule.petershouse.invalid (10.4.0.1) 16.445 ms 19.240 ms 19.277
ms
Q1. Why is 10.4.0.1 reported twice?
Q2. Why does traceroute from Dalton stop at 10.4.0.1
rather than continue to 24.108.32.1 and etc.
I'm asking in this forum because I have no insight
whether this problem is in routing, or in Exim
configuration or in Shorewall configuration or in
OpenVPN configuration or in the ISP. Any clues
appreciated.
Thanks, ... Peter E.
On Nov 2, 6:08*am, peasth...@shaw.ca wrote:
What's Dalton's default route? What source address is Dalton choosing
for the traceroute?
About 8 out of 10 times, when a traceroute appears to stop at node X,
it's actually stopping one node further, as the next node has no idea
how to get the reply packets *back*.
Do a tcpdump on both Dalton and Joule and repeat the traceroute.
DS
David & others,
On Sun, 2 Nov 2008 18:20:12 -0800 (PST) David Schwartz wrote,
ds> What's Dalton's default route?
dalton:/etc/openvpn# netstat -r
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window
irtt Iface
shawmail.cg.sha joule.petershou 255.255.255.255 UGH 0 0
0 tun0
64.59.128.135 joule.petershou 255.255.255.255 UGH 0 0
0 tun0
joule.petershou * 255.255.255.255 UH 0 0
0 tun0
142.103.107.128 * 255.255.255.128 U 0 0
0 eth0
172.24.1.0 * 255.255.255.0 U 0 0
0 eth3
172.23.5.0 joule.petershou 255.255.255.0 UG 0 0
0 tun0
default 142.103.107.254 0.0.0.0 UG 0 0
0 eth0
The default route is conventional Internet;
but the route to the shawmail addresses,
24.71.223.43 and 64.59.128.135, is through
the OpenVPN tunnel using tun0.
ds> What source address is Dalton choosing for the traceroute?
.... Do a tcpdump on both Dalton and Joule and repeat the traceroute.
While tshark was running on Dalton I ran the traceroute.
As Wireshark displays the tshark log, the content
of a tunnel packet is not evident. I would need to
decode the binary data to be convinced a packet
contains traceroute data; this would be a challenge.
The pattern of tunnel packets is consistent with the
trace but I am not certain of the source address.
I still need to install tshark on Joule; it might
help.
What else can be done?
Thanks, ... Peter E.
