What is incoming/outgoing policy in the router setting? and is there any difference between incoming/outgoing policy and incoming/outgoing direction?
When I want to configure my router to allow a specific device(s) to connect the Internet trough my router using its MAC address, is it allowing outgoing or incoming?
what is the difference between source MAC and destination MAC address?
The MAC (Media Access Control) address is a value associated with the network interface of the device (PC, mobile phone, tablet, IP Camera,etc). On Windows using ipconfig /all the MAC appears as physical address.
Each device have a unique MAC configured from factory that is unique on the world. So there is no chance of two devices with the same MAC.
When two devices (for example two PCs) have to communicate on a LAN, they use a protocol as IP but to access the LAN cable or the wifi they need to use the MAC address. IP provides a way to make a relation of MAC address and IP, it's called ARP.
On Windows, go to Command Prompt use the command arp -a and you can see a table that relates IP to MAC.
For example, suppose we have a PC called A with IP 192.168.2.1 and MAC 15-c5 and a PC called B with IP 192.168.2.2 and MAC 2b-f7.
If A sends data to B, then A takes that data and put it inside an IP Packet with Source IP address 192.168.2.1 and IP destination address 192.168.2.2. The IP packet is like an envelope that encapsulates the data.
To access the LAN, the IP Packet must be put inside an Ethernet frame. The Ethernet frame will use source MAC address 15-c5 and destination MAC address 2b-f7. The ethernet frame is an external envelope that makes it easy to move frames on the LAN.
It's typical that home routers have a menu that let block source MAC address in a way that they can't connect to the wifi or to internet.
