Unable to connect?

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Unable to connect?

Postby AntGaz » Fri Dec 28, 2007 7:47 pm

Hi,

I'm a very new member of the DIMES Project, and I'm having a few problems with sorting everything out.

My PC is hooked on to the network of my university, and I'm not sure whether that network is blocking connections or not.

This morning everything booted up normally, the graph window was showing some connections in a cloud and I started gathering some points on the Stats Page, although the message log said that there were no IPs replying:

Image

Image

But now, there are no new connections in the graph for several hours, and the message log still tries to PING and TRACEROUTE random IPs with the same messages over and over again, see above. When I view the connections in the cloud by ISP, they all seem to be part of the VUB network (university).

Is there a way to search for a connection outside the network by tracerouting?
And the weird thing is: I'm still gaining points..
Screen of my Properties:

Image

BTW: I haven't installed any kind of firewall on my computer.[/url]

If anyone can help, please reply!

EDIT: Oh, and I'm using the 0.4.3 client and Java 6 Update 3
AntGaz
 
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Joined: Fri Dec 28, 2007 7:10 pm

Postby UDi » Sun Dec 30, 2007 7:45 pm

What you raise is interesting and we will check some of the stuff you're talking about.

Some things:
1. The "Destination host did not reply" does not have to mean that you don't leave your LAN. It might also mean that we measure to a non-existing IP, so we have the trace, but not the final destination.

2. How many hops do you have inside the university? you should only see one or two hops, unless the university network is pretty large.

3. If you don't leave the local network, you should not gain points. We will look at this.

4. You can try crawling using the agent. Simply crawl a website, and look for the results. Also, you can try traceroute (unix) or tracert (windows) for a destination, and see if this works.

5. The situation you describe is quite complex, since you say that everything works, and then stopped. Either that someone installed a FireWall, or that an existing FireWall decided that your host is "hostile" and then stopped allowing you to do ICMP/UDP. You should check manual traceroute from the command line, and see if this works.
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Postby AntGaz » Wed Jan 02, 2008 3:55 pm

OK, thanks for your help already, and I checked some of thing out you pointed out:

1. I understand that not every IP that's being measured exists, but is it normal that not one IP can respond to my client? It usually runs 8 to 12 hours a day, which is why it seems unlikely to me that it doesn't measure even one existing IP.

2. Normally I have around five hops, from which there is one with my university's ISP and four with an Unknown ISP, but I suspect the latter four are also part of the network, since their IPs are very alike (maybe mailservers or databases):

Image

3. My score rate hasn't really changed I think. The last two days however, I was at my home town to celebrate newyear, so my PC was mostly turned off those days.

4. I've tried extensively to crawl websites: Belgian and foreign sites, Traceroute and Ping, UDP and ICMP.
Here are some of the results for http://www.demorgen.be (newspaper):

Traceroute UDP, max. depth and max. IP's
Code: Select all
INFO: TRACEROUTE 195.130.156.115 UDP
2/01/08 15:59 dimes.measurements.Measurements execute
INFO: TRACEROUTE 194.78.225.121 UDP
2/01/08 15:59 dimes.measurements.Measurements execute
INFO: TRACEROUTE 4.79.4.165 UDP
2/01/08 15:59 dimes.measurements.Measurements execute


Ping UDP, max. depth and max. IP's
Code: Select all
INFO: PING 194.246.101.31 UDP
2/01/08 16:15 dimes.measurements.Measurements execute
INFO: Destination host didn't reply.
2/01/08 16:15 dimes.state.KeepAliveTask run
INFO: Running KeepAlive Task
2/01/08 16:15 dimes.measurements.Measurements execute
INFO: PING 4.21.179.37 UDP
2/01/08 16:15 dimes.measurements.Measurements execute
INFO: Destination host didn't reply.
2/01/08 16:16 dimes.measurements.Measurements execute


None of the measured IP's replied and in both cases the cloud remains the same with 5 nodes.

However, if I crawl the website of my university some packets are returned from some of the Pinged IP's and, when tracerouted, the cloud in the graph grows bigger and is almost the same like the one in my first post (structure, size and connected IP's).

5. I don't know how I can manually traceroute an IP from the command line..
Is it possible that my university has a system of blocking connections in a way that my computer (or the client) doesn't recognise? And thus, thinking traffic is free and unblocked, the client tries to measure IP's outside of the LAN (explains why every destination host doesn't reply) and sends the wrong(!) results to your servers (epxlains my gain in points).
This is a purely hypothetical situation, I'm not a networking specialist so I have no clue whether this is even possible or not!

and BTW: A Happy Newyear To All!! :D
AntGaz
 
Posts: 2
Joined: Fri Dec 28, 2007 7:10 pm

Postby UDi » Mon Jan 07, 2008 8:32 am

You probably have a large LAN in the university, that is why you have several hops before the packet attempts to exit the LAN into the Internet.

Each measurement you do, that has more than one hop gives you credit. Since you have ~5 hops, you get points for that. However, your measurements do not explore the Internet. The data that is sent to our server from your agent is correct.

Your university probably has a firewall or packet filter that either does not allow you to do measurements from it, or does not allow packets to enter.

To preform traceroute from the command line, if you're using Windows:
- Run cmd (WIN+R, then write cmd).
- Write: tracert <destination> in the command line.

In linux, simply start a command prompt and use traceroute command.

Let us know if you manage to do traceroutes from the command line.
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