My (old) ZyWall 2 router/firewall is giving error message that I haven't been able to find the source for. It is configured as a plain router (static wan IP), DHCP server on the LAN side, and what is called Full Feature NAT. Everything seems to work well, but many times every day there are error messages (alerts) saying:
No. Time Source IP Destination IP Note
1|08/17/2014 11:37:17 | | |
Discard packet, the vlan tag is undefined. vlanTag=7
End of Alert
I have no equipment on the LAN side using VLAN. WAN side is having an official IP address (part of my xxx.xxx.xxx.xxx/25 network). Since the alert doesn't indicate any source or destination address, it seems difficult to debug.
Is there a way to find what is causing these alerts?