Category Archives: Networking

Network trace without NetMon, wireShark, etc… Part 2

MC91021636214As I told you in the previous episode, there is more than just capturing without installing any software. Much more, actually. There is a .cab file which contains many files: 33 to be accurate (at least in my case). The files contain the heck of information about the computer’s networking configuration as well as logs. Let’s take a look at those files:

 

1) adapterinfo.txt: contains info about your NICs’ drivers:

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How can this be useful? Easily, say, you see the driver for a physical NIC which was issued 5 years ago: why not to upgrade it first? Anyway, this can give you the starting point for troubleshooting.

2) dns.txt: this one contains the output for ipconfig /displaydns command which gives us the content of the DNS client cache

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3) envinfo.txt: all you want and even more about the wireless network. Drivers with supported authentication and cipher options, interfaces and their state, hosted networks, WLAN settings, profiles and more and more…

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4) filesharing.txt: nbtstat –n, nbtstat –c, net config rdr, net config srv, net share

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5) gpresult.txt: no comments

6) neighbors.txt: arp –a, netsh interface ipv6 show neighbors (yeah, calling netsh from netsh… inception… 😉 )

7) netiostate.txt: in my case there were Terede settings

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8) osinfo.txt: at first it looks like systeminfo output, but actually it is somewhat different, yet can prove useful.

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9) Report.etl: trace log file. I haven’t yet took a look into it. Probably it can be good for a deep troubleshooting

10) wcninfo.txt: wireless computer network information. Services status, files information and again interfaces info, ipconfig, and more…

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11) wfpfilters.xml: I haven’t yet undertook a close investigation on the file, but seems like the file contains firewall rules in XML format

12) windowsfirewallconfig.txt: config for the firewall. Is it turned on, global settings and all that stuff

13) several other files, which contain various event logs related to networking, registry keys dumps and other info

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14) Report.html: an .html file which contains links to the files above

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Well, that’s it. Actually, while troubleshooting some incidents I was forced to request some info several time, just because I didn’t know what exactly I was going to need and I didn’t want to frustrate users with many commands or sending them a .bat file. Now I can give them only two commands and voila! I love it, really. IMHO this ability is just awesome even without taking network traffic capture, so I strongly advise to remember it!

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Network trace without NetMon, WireShark, etc…

MC910216362[1]It is often necessary to capture and analyze some network traffic to troubleshoot a problem. Usually, it requires to install some software package similar to several stated in the subject to this article. It’s ok, when the computer in question is, say, your laptop, or its user is at least advanced user, has administrative permissions and it is permitted by a security policy to install some new software. But what if it is not the case? A user is some sales manager who don’t want to spend their time installing anything? Or this is a server, where you cannot change anything?

To cut a long story short, recently I’ve run into a totally awesome blogpost, where among other truly interesting things (the blog is in the top 5 of my most favorite, if not the most interesting, BTW) there was a solution for such a situation.

In short, you don’t have to install, say, Network Monitor onto a Windows7/2008 R2 box to get network capture. It can be done with the built-in tool, that is netsh. You still need

1) to be a local admin on the computer you are tracing

2) NetMon to analyze the package you receive after the capture is complete. But you can do it on any computer you wish.

How does it work? Just excellent 😉

1) Start the trace

netsh trace start capture=yes tracefile=<PathToFile>

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2) Then reproduce the problem. I started my chrome (to much open tabs in IE 😉 ) and went to www.microsoft.com.

3) Then stop the trace:

netsh trace stop

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Please notice, that the trace created two files: .etl and .cab. The ETL one is where our network trace is placed. The second… It makes the method even more awesome, but I will dedicate the next blog post to it.

4) Open the trace on any computer where you have Network Monitor installed:

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Oops… What’s with parsers? If we take a closer look at the interface we’ll see the following:

Process: Windows stub parser: Requires full Common parsers. See the “How Do I Change Parser Set Options(Version 3.3 or before) or Configure Parser Profile (Version 3.4)” help topic for tips on loading these parser sets.

Well, some parsers are definitely not turned on. Let’s do it now, it’s easy (I have NetMon 3.4). Go to tools->options

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Look at Parser Profiles tab:

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and turn on the Windows profile by right clicking it and selecting Set As Active option:

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That’s what we were looking for:

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5) Now do all the NetMon stuff, for example I was looking for Chrome activity and, say, I need to look at DNS requests:

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Isn’t that great? No, it is simply awesome, because we haven’t yet take a look at .cab file, which contains tons of useful info. But we’ll do it in the next article.