I can’t ping other devices, I can’t ping RB from other devices, no TCP/IP available from inside, I can access to RB only through Winbox-MAC
I supposed there could be something wrong with OpenVPN server (I run OpenVPN server on different RB, same board model and ROs version) but in this case I have just a router.
Reboot: not solved.
Removed all firewall rules: not solved.
As further test I removed all entries in ARP list: this solved issue.
How to debug?
As further test I removed all entries in ARP list: this solved issue.
ARP should be a very dynamic list, of IP-address/MAC address tuples, based on ARP requests and responses. Is the ARP setting on the interfaces anything other than “enabled”?
Other possible ARP/MAC problem is after restoring a backup from another device, which contained the MAC addresses from that device. (“Reset MAC address” should solve that one)
For debugging … you have tools “TORCH” and “Packet Sniffer” to see what happens in that router. You have tool “Traceroute” to see how the packets are routed.