[NEBULA] NAP102 Becoming Disconnected Frequently

CSmith_STC

I have one customer site where their three NAP102 APs become disconnected from the NCC regularly.
I can't see the reason for this; any suggestions please?

Current setup:
 - Static DHCP address allocated by SBG3500 router on site
 - APs configured to gather their network settings from DHCP

When AP is showing as disconnected from NCC I can:
 - Ping AP from local switch
 - Ping AP from local gateway (SBG3500)

Public IP address is showing correctly
LAN IP addresses may or may not show correctly in NCC.

Thank you

Zyxel_Dean

Hi there @CSmith_STC,

It's quite strange it disconnects regularly, could you describe what is the pattern of it? every few hours or minutes? something like that.
When it's disconnected, does it show offline or just some items don't display? Sometime when the device reconnects to the server there is a gap when the device information is not yet updated and shows empty, such as the LAN IP you are seeing.

In our experience, if it is regularly being disconnected, you might have to check your firewall or antivirus if it is disconnecting the sessions from the device to NCC, or even have to query the ISP in some cases. 
Please check if there is anything in your network blocking/disconnecting sessions belonging to TCP port 6667. 

You can refer to this post as of what access to allow for Nebula devices.
https://businessforum.zyxel.com/discussion/83/how-does-nebula-devices-communicate-with-nebula-control-center#latest

Let us know how it works out!

-Dean

CSmith_STC

Hi @Nebula_Dean
The link doesn't clearly define in which direction the ports need to be open.
Outbound access from LAN to WAN via the customer firewall is allowed for all protocols.

By default you are shown statistics for a 2hr window.
Each AP is shown as being Offline for at least 1 minute in each 2hr period; usually a couple of times.
In addition at least of of the APs, and not always the same one, is shown as offline for 5 minutes or more.

Thanks

Chris

Zyxel_Dean

Hi Chris, 

Another thing I can think of, can you check if SBG3500 WAN interface has the MTU size of 1500? If not please set it to 1500.

The traffic from port 6667 is initiated from the device, so it should be fine if the outbound access is allowing all port. Just to be safe can also you check of there are any syslogs in SBG3500 that may relate to dropping port 6667 sessions?

I suggest you submit a ticket if the above steps are checked, this way we can get more details of the site/devices and find where's the problem.
You can find it in NCC> Help > Support request , to submit a case to us.

-Dean

CSmith_STC

Morning @Nebula_Dean
The MTU of the WAN interface (VDSL) of the SBG3500 is set to the maximum allowed value of 1492 bytes. I'll log a case / support ticket.

Thanks

Chris