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Network Devices drop off then come back

Posted on 2016-07-15
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Last Modified: 2016-07-18
Hello

Thank you for taking the time out to read my question. Your time and expertise is greatly appreciated.

I recently took over mgt of a network that has several VLAN's. The last provider setup the network then disappeared. The client is now having issues:

- Cameras drop off the network, then comeback. When it comes back another one drops off. (These devices have static IP's)
- Devices on Data VLAN will loose internet connection. For example a laptop on wifi will lose connection and then won't be able to connect back. Says limited connection and device does not get an IP address.

I've only so far noticed this issue on VLAN1 & VLAN4

These are the VLAN's:

VLAN1: Management, Security (NAS, POE Cameras)  (static IP)
VLAN2: Voice  (DHCP)
VLAN3: Video Streaming  (DHCP)
VLAN4: Automation, DATA, WIFI (DHCP)
VLAN5: Not Used
VLAN6: Future Guest Wifi (currently not used)

Everything in the building is IP controlled (lights, hvac, security, alarm, doors, shades, TV's, sound) All the networking hardware is from Control4
http://www.control4.com/
http://www.residentialsystems.com/news/0002/control4-reveals-new-pakedge-price-points/88144

VLANS and DHCP is coming off the router. There are a total of 6 24 port gigabit switches that I found so far. I far as i can tell the entire network is gigabit.

I automatically suspected that there are issues with DHCP. However, both static and dhcp devices on VLAN1 and VLAN4 suffer from this issue. I did review all the DHCP scopes and they look fine.

Yesterday i had to reboot the router b/c several wireless laptops (including mine) dropped off the network and would not connect back. I then patched my laptop into VLAN1 on one of the switches and was not able to get an IP there either. I finally had to reboot the router. Once i did that, the devices were able to connect including my laptop which was patched into one of the switches on VLAN1.

I used wireshark to perform a packed capture on VLAN1 hardwired and VLAN4 wireless. At the moment I lack the expertise to analyze the packet capture. They are located here Please review it if you can and tell me if you can spot any evident issues.

My next steps:
 - reboot entire network including all network devices
 - review VLAN tagging on all switches
 - enable spanning tree on managed switches
 

Any and all constructive feedback/recommendations are greatly appreciated ahead of time.

Please let me know if you need more info or have additional questions.

Thank you advance.

~Milosz,
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Question by:CMITStamford
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Expert Comment

by:John Hurst
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For example a laptop on Wi-Fi will lose connection and then won't be able to connect back. Says limited connection and device does not get an IP address

Start here with this machine.

Look in Device Manager, wireless card, properties and uncheck the setting that says "Allow this card to be turned off"
Go to Windows Power Management (Control Panel) and set the Wireless card for Maximum Performance AC and Battery.
If there is a third party power manager, disable it at least temporarily.

Shut down, start up and test this laptop for losing Wi-Fi.
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Author Comment

by:CMITStamford
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Hello John

Thank you for your feedback.

This issue persists on both MAC and Windows laptops and does not address the fact that poe cameras with static IP's on VLAN1 drop off as well.

I don't believe that this is the root cause.

Thank you again.
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Expert Comment

by:John Hurst
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Try updating the firmware on the routers that have the VLAN's

My step above was a test. Without testing it is hard to know.
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Author Comment

by:CMITStamford
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Firmware is up to date or router and managed switches.

Thank you
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by:John Hurst
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Consider Wi-Fi channel interference (look at your space with inSSIder4)  and then also consider compatibility of the Wi-Fi with your network cards (this has happened to me).
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Author Comment

by:CMITStamford
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I'm also having same issue with devices on VLAN1 which is all hardwired.
I really need someone to take a look at the packet captures i provided.

Thanks John
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by:John Hurst
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I cannot open your files. Not with SnagIt, not with Lview, only with Ultra Edit and then I just see HEX.
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Author Comment

by:CMITStamford
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Hi John

This file includes both PCAP and PCAPNG both created in wireshark.

https://cmitstamford2-public.sharepoint.com/SiteAssets/directions/Packet%20Captures.zip

Thank you
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by:John Hurst
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I use Comm View by Tamosoft and do not have Wireshark running. Still, I was able to open a PCAP file with Notepad (which is one option to open PCAP files if one googles for applications)

What is this?  I turn UPnP OFF on my routers.
SERVER: Linux/2.6.18_pro500-davinci_evm-arm_v5t_le, UPnP/1.0, Portable SDK for UPnP devices/1.6.17

Half way down, there appear to be big videos being transferred. Is this hampering throughput?

Take 3 wired machines and put them on a different switch with no VLAN's hooked up to your internet source. Do they drop connections?
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Author Comment

by:CMITStamford
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What is this?  I turn UPnP OFF on my routers.
Did not realize that was on. I will turn off for security reasons.

SERVER: Linux is the home automation controller. This is the main automation controller for everything in the building (video streaming to TV's, lights, hvac, alarm, video surveillance, doots, etc..)

Half way down, there appear to be big videos being transferred. Is this hampering throughput?
How would i tell?

Take 3 wired machines and put them on a different switch with no VLAN's hooked up to your internet source. Do they drop connections?
The POE cameras are on hardwire connected to switch with only VLAN1. They drop connection.

Thank you for your time and input John.
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John Hurst earned 500 total points
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Half way down, there appear to be big videos being transferred ... How would I tell?

I saw the large volume of binary data following lines with video in them. I think that is what it is and then may be swamping your network (which would in turn cause connections to drop and come back). I have see a similar thing at a client that was swamping a low end connection with video.

The reason for a test that goes around the VLAN's is to see if they may be part of the problem. VLAN's a software routing within the switch.
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Expert Comment

by:akahan
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Are the static IP addresses within the DHCP scope?  They shouldn't be.

So for example, on VLAN4, if the addresses being handed out by the DHCP server range between 192.168.1.2 and 192.168.1.50, then the static ip addresses should NOT be within that range; they should be 192.168.1.51 and up.

If the static IP addresses are within the range of the DHCP pool, then you will have intermittent problems of the sort you describe, whenever a DHCP device gets assigned the same address as is already assigned statically to another device.
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Author Comment

by:CMITStamford
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I am fairly certain that all static IP's are outside of the DHCP scope. I will review to make sure.

Thank you
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Author Closing Comment

by:CMITStamford
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Thank you for your help John.

Have a nice week.
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by:John Hurst
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You are very welcome and I was happy to help.
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