Tips to solve your network problems


#1

I know a lot of people just want to plug in a box and have it work and that is coming in the future with newer standards but for now we have to use what we have. Most people are not network admins and know little about networking and that causes a few problems that I know many people think shouldn’t exist. In reality though there isn’t much that can be done to prepare for every possible network configuration in use.  

The absolute worst way you can troubleshoot problems with networking is to just randomly start trying things. There are too many variables and turning things on and off , changing settings without knowing what the problem is would be like a doctor, having  never examined you, prescribing something based on a phone call. don’t know about you but I wouldn’t use that doctor :slight_smile:

I wrote a tutorial a few months back on using wireshark . Wireshark is a program that lets you see what the computers on the network are saying to each other.  Without something like it you have no way to know if a connection went bad because the password was wrong or if it was interference from a sunspot. 

The old tutorial is here:

http://community.wdc.com/t5/Networking/How-you-can-find-what-is-causing-the-problem-with-network/m-p/11838#M953

I know people do not like to install 3rd party software so here is a new tutorial using 

Microsoft Network Monitor 3.4

http://www.microsoft.com/downloads/details.aspx?FamilyID=983b941d-06cb-4658-b7f6-3088333d062f&displaylang=en

It works on all MS OS. 

Install the typical install when you run it. 

Unplug the WDTV Live for about 10 seconds then plug it back in but leave it off.

Start the program , look in the Select Networks window

Uncheck everything except the main network interface the Live is sharing with your pc.

In the top window select New Capture Tab

Press the F5 Key

You should now see a bunch of traffic on the middle window on the right. That is all the traffic  going on within your network. 

Turn on the WDTV Live now.

Look for something to appear like this:

WDTVLIVE   255.255.255.255 ARP ARP:Response, 192.168.0.6 at 00-90-A9-74-22-24

This means the WDTV Live is announcing itself to the network, sort of a hello and asking who is there.

Next you should see:

WDTVLIVE   192.168.0.1 ARP ARP:Request, 192.168.0.6 asks for 192.168.0.1

The player has determined that 192.168.0.1 is my routers IP and wants to use 192.168.0.6 for itself.

Next it starts to announce itself and what services it can provide to other devices.

WDTVLIVE 192.168.0.255 NbtNs NbtNs:Registration Request for WDTVLIVE <0x20> File Server Service, 192.168.0.6

WDTVLIVE 192.168.0.255 NbtNs NbtNs:Registration Request for WDTVLIVE <0x03> Messenger Service/Main name, 192.168.0.6

WDTVLIVE 192.168.0.255 NbtNs NbtNs:Registration Request for WDTVLIVE <0x00> Workstation Service, 192.168.0.6

WDTVLIVE 192.168.0.255 NbtNs NbtNs:Registration Request for WORKGROUP <0x00> Workstation Service, 192.168.0.6

WDTVLIVE 192.168.0.255 NbtNs NbtNs:Registration Request for WORKGROUP <0x1E> Browser Service Elections ,92.168.0.6

Next it tells the network that if there isn’t someone to be in control of the list of files on the network that it is willing to do that job for the network. 

WDTVLIVE   192.168.0.255 BROWSER BROWSER:Host Announcement, ServerName = WDTVLIVE

These are where it is looking for Upnp device support , thinks like media player Play To

WDTVLIVE   239.255.255.250 SSDP SSDP:Request, M-SEARCH *

My pc has heard the request from the player and tells it so,.  The 192.168.0.3 IP is my pc and the 192.168.0.6 IP is the player. So my pc is asking for the Live to listen to it. sort of a 'Hey you we need to talk !"

HOME-PC WDTVLIVE   ARP ARP:Request, 192.168.0.3 asks for 192.168.0.6

T he player replies telling it " Okay, lets talk but we need to do it using these ports and information I will send."

WDTVLIVE   HOME-PC UDP UDP:SrcPort = 32771, DstPort = 53581, Length = 293

My pc replies with a Get , basically asking the player for a list of what it can do.

HOME-PC WDTVLIVE   HTTP HTTP:Request, GET / 

Next they will do a bunch of talking between each other to exchange information on what features they support, if media player will work, etc. After that finishes go to video and network shares on the player.

You should see your pc listed . Click on it and access the share but do not start playing a file just yet.

It looks like this:

Player requesting to talk to my pc to do a file operation. 

WDTVLIVE   Home-PC NbtSS NbtSS:SESSION REQUEST, Length =68

My pc responding okay lets talk about files. They haven’t agreed to do anything but talk at this point.

HOME-PC WDTVLIVE   NbtSS NbtSS : POSITIVE SESSION RESPONSE, Length =0

The player wants to talk using samba and now they need to decide on a common language so the player tells the pc what languages it can speak. 

WDTVLIVE   HOME-PC SMB SMB:C; Negotiate, Dialect = PC NETWORK PROGRAM 1.0, MICROSOFT NETWORKS 1.03, NT LM.012

The pc replies that it prefers NT LM.012 as the language .

HOME -PC WDTVLIVE SMB SMB:R; Negotiate, Dialect is NT LM 0.12 (#9)

With the language chosen the player tells the pc what group it belongs to:

WDTVLIVE   HOME-PC SMB SMB:C; Session Setup Andx, NTLM NEGOTIATE MESSAGE, Workstation Domain: WORKGROUP, Workstation Name: WDTVLIVE

The player then sends its login information to the pc, on my pc I have a user account called wdtv just for the player.

WDTVLIVE  HOME-PC SMB Domain: WORKGROUP, User: wdtv, Workstation: WDTVLIVE

M y pc decides it is valid and sets up the connection and the player acknowledges it is ready using that account.

HOME-PC WDTVLIVE   SMB SMB:R; Session Setup Andx

WDTVLIVE   HOME-PC SMB SMB:C; Session Setup Andx, Account = wdtv

The player ask my pc for a list of the files it has on the share and how to get them, mine are in a directory named TV

WDTVLIVE HOME -PC SMB SMB:C; Tree Connect Andx, Path = \192.168.0.3\TV, Service = ???

N ext the live wants to know about the file system on the pc, what limits it has(read/write) etc

WDTVLIVE   HOME-PC SMB SMB:C; Transact2, Query FS Info, Query FS Device Info (NT)

SMB:C; Transact2, Query FS Info, Query FS Attribute Info (NT)

SMB:R; Transact2, Query FS Info, Query FS Attribute Info (NT), FS = NTFS

SMB:R; Transact2, Query Path Info, Query File All Info, FileName = \TV

**SMB:C; Transact2, Find First2, Directory Info (NT), Pattern = \*

The pc then sends its information

HOME-PC WDTVLIVE SMB SMB:R; Transact2, Find First2, Directory Info (NT)

Once you select a file on the player it will look like this , the player is asking the pc for this file, LostS01E12.avi

W DTVLIVE HOME-PC SMB SMB:C; Transact2, Query Path Info, Query File All Info, Pattern = \LostS01E12.avi

The pc responds with how to get the file:

*HOME-PC WDTVLIVE SMB SMB:R; Transact2, Query Path Info, Query File All Info, FileName = \TV* LostS01E12.avi

The player sets up the connection to the pc and tells the pc what time in the file it should start from. 

WDTVLIVE   HOME-PC SMB SMB:C; Nt Create Andx, FileName = \LostS01E12.avi

HOME-PC WDTVLIVE   SMB SMB:R; Nt Create Andx, FID = 0x4004 (   LostS01E12.av i@#18662)

WDTVLIVE   HOME-PC SMB SMB:C; Read Andx, FID = 0x4004 (\   LostS01E12.av i@#18662), 16384 bytes at Offset 0

HOME-PC WDTVLIVE FileTypeContent FileTypeContent:FileName =\ LostS01E12.avi@#18662

And finally the file selected starts to play, these will repeat for every part of video streamed until the end of the stream.

HOME-PC WDTVLIVE TCP TCP:[Continuation to #30723]Flags=…A…, SrcPort=Microsoft-DS(445), DstPort=55834,

While this may not give you the exact fix for your setup it should give you an idea of what it looks like when everything is set up correctly. Hopefully that will give you a starting point to find the problem. If you get stuck post at what point and the message from the network monitor you have questions about.