Troubleshooting Network

ThirdEyeTech used Ask the Experts™
We are having a problem communicating with 3 devices on our network.  

Situation: We are moving an app from one server to another.  The original server has had few issues communicating with the three time clocks on the network.  The new server is able to ping one (1) of the three (3) clocks but can't telnet to any.

Network:  The network consists of 4 switches and are connected as follows

SW1 3COM Baseline 2816 Port 1 <-> SW3 Port 13
SW2 3COM Baseline 2024 Port 12<-> SW3 Port 12
SW3 3COM Baseline 2824 (see others)
SW4 HP V1910 24G Port 24 <-> SW3 Port 23

Server 1 (original server) connected to SW3 Port 21
Server 2 (new server) connected to SW4 Ports 17, 18, 10, 19 (respectively 1-4)
 - These connections are teamed.  These connections were originally spread across all four switches until the problem was discovered, then they were all placed on switch 4

Switch 4 has 3 VLANs - 1 (default) carrying all basic non-specific network traffic
VLAN50 - Secure wireless (Untagged ports 1-7 + PVID) (Tagged Port 24)
VLAN200 - Unsecure internet only wireless (Tagged Ports 1-7, 24)

I am able to ping and telnet from server 1 to all 3 clocks.  I am only able to ping 1 clock from server2 and telnet to none.

Server 1 Windows 2003 SBS w/ 1 network port
Server 2 Windows 2008 R2 w/4 network ports teamed together

Any and all assistance and suggestions are appreciated.

Thank you for reading my post.
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First suggestion -- get rid of teaming!  This feature always complicates things, and is an obvious difference.

Second, where are the timeclocks located?

Finally, you may wish to use wireshark and attach to each of the switches to see what is happening to the traffic. This could be as simple as a bad cable, but I doubt it.
Curious as to what brand of NIC's you have in the team.  Broadcom? Sounds similar in nature to something I encountered before.


I have deleted the team and disconnected all network cards except port 1.  I moved the connection on port 1 to SW3.  I am now able to ping all devices on the network.

Thank you BillBach.  They are all located on the same subnet and physical LAN.  Some of them are connected with fiber for part of the run.

I would like to be able to add the team back but obviously there is an issue.  Does anyone know is there a way to make this work?  

Separate thought could there be an issue with MSTP causing slowness.  I have confirmed several times there is only one connection from each switch to SW3 and no connections between the switches.  Is it possible there could be a switch loop.  If so would wireshark be able to see it and if so what would it look like.


Getzjd, yes they are all Broadcom with update drivers, and firmware.
I was going to say I have been having some issues with the various Broadcom drivers and the NIC's in a team.  Periodically, the entire team will go offline.   STP is disabled on the switches and viewing spanning tree status when they are offline does not indicate any blocking.   I broke the team and am just running on 1 nic as that site only has a handful of users.   I havent given any further attention to it since the team is not technically needed.    Event viewer does not show anything other than detecting there is no LAN connection.

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