Zyxel Nebula Switch Troubleshooting Guide

Zyxel_Kay

This troubleshooting guide will help you to do some quick check and test for your Nebula switch.

Switch is offline on NCC

1. Does the switch has IP address?
   1. Download and install ZON utility on your PC to scan the Switch
      • Register and download link: https://www.zyxel.com/global/en/products/management-and-reporting/zyxel-devices-installation-tool-zon-utility
   2. If the Switch doesn’t have an IP address, please check your DHCP server or using ZON utility to configure static IP for the Switch
   3. Don’t get DHCP IP
      
   4. Get DHCP IP
      
2. Does the Switch connect to the Internet?
   1. Access Switch via Telnet/SSH/Console
   2. Ping 8.8.8.8 and your default gateway
   3. Please check Next page for the different result
      
      
   4. If ping 8.8.8.8 fail and default gateway fail
      => Please check the routing and physical connection between Switch and gateway
   5. If ping 8.8.8.8 fail but default gateway OK
      => Please check your default gateway for the Internet connection
3. Can the Switch resolve NCC server’s domain?
   1. Access Switch via Telnet/SSH/Console
   2. Ping d.nebula.zyxel.com
      Note: It is normal that our server doesn’t reply the ping request
   3. Please check next page for detail information
   4. Please check if our NCC server domain can be resolved as one of the following:
      • 34.243.116.158
      • 34.246.20.161
      • 52.16.90.243
      • 52.210.12.1
      • 52.210.229.217
      • 52.48.115.44
      • 54.73.103.137
      • 54.76.217.223
      • 54.154.22.135
   5. The IP address will also update in Help center > Firewall information on NCC
      
   6. If the Switch shows “unknown host”, please check your DNS server setting or try 8.8.8.8 as DNS server on Switch(You may configure it on Local GUI of Switch)
      
4. Is there any firewall rule blocks NCC protocol?
   1. Please check if your network or ISP has blocked 4335/6667 port
   2. You may visit http://portquiz.net:6667/ or http://portquiz.net:4335/ via IE or Edge browser to check
      
5. Does the firewall/modem change its MTU size?
   1. Please check if your firewall/modem has changed its MTU size. If yes, please change it to 1500.
      
6. Is the system time of the switch correct?
   1. Please check with the command "show system" to check the system time.
   2. If the system time is incorrect, please check if your firewall blocks UPD 123.

Upgrade firmware fail

1. Can DNS server resolve firmware server’s domain?
   1. Access Switch via Telnet/SSH/Console
   2. Ping firmware.nebula.zyxel.com
   3. Please check next page for detail information
      
      
   4. If the Switch shows “unknown host”, please check your DNS server setting or try 8.8.8.8 as DNS server on Switch.
      
      

Still have problem

If the issue persist after doing those troubleshooting steps, please download the Tech-Support file from the Switch local GUI and contact Zyxel Support:

Management > Maintenance > Tech-Support > All

Ways to contact Zyxel Support

• If you are using Nebula Base Pack, you may post a new topic on our Forum (Help center > Support community) or contact our local support
• If you are using Nebula Pro Pack, you may raise a ticket on NCC directly. Help center > Support request > Direct Support > New Case.
• Please do remember to enable Zyxel Support Access on your organization. Help > Support request > Zyxel Support Access.