Computer networks ( data transmission )

Question

If I am sending data from source to destination through a router and router have three interfaces possible then during sending a data packet from sender to receiver via router how many times the packet will go through data link layer ? ( does the answer would be same if we have 2 interfaces at router or any number of interfaces ?)
Expalin please anyone :)

Answer 1

When you send a data packet from a source to a destination through a router, the data packet goes through the data link layer twice. First, when the data packet leaves the source and is transmitted to the router, it is wrapped in a special envelope called a "frame" using protocols like Ethernet. This frame is then sent over the physical link to the router.

Once the frame reaches the router, the router "unwraps" the frame and examines the contents of the data packet at the network layer to determine where it should be forwarded. Then, the router creates a new frame using data link layer protocols and encapsulates the data packet into this new frame. This new frame is then sent out of the appropriate interface toward the destination.

So, in total, the data packet passes through the data link layer twice: once when it leaves the source and once when it is transmitted from the router to the destination.

Comments

I have read like if we have 2 interfaces on router then while transferring from source to destination a packet encounters dll 4 times , but i am confused about what if we have 3 interfaces .

And cant match what you said and what i know .

:(

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Router consists of 1 network layer and as many data link layers as interfaces present in the network.

given question says about 3 interfaces at the router which means there are possible of 3 datalink layers(at router) and 2 datalink layers (at sender side and reciever side)

then during sending a data packet from sender to receiver via router 5 times the packet will go through data link layer.