Contents
How does the router decide where an incoming packet should go?
A primary function of a router is to determine the best path to use to send packets. To determine the best path, the router searches its routing table for a network address that matches the destination IP address of the packet.
How does a packet and router communicate?
When a packet arrives at a router, the router examines the IP address put there by the IP protocol layer on the originating computer. The router checks it’s routing table. If the network containing the IP address is found, the packet is sent to that network.
What happens when a router receives a packet with a TTL of 1?
When a labeled packet is received with a TTL of 1, the receiving LSR drops the packet and sends an ICMP message “time exceeded” (type 11, code 0) to the originator of the IP packet. This is the same behavior that a router would exhibit with an IP packet that had an expiring TTL.
What is inside the router?
The switching fabric connects the router’s input ports to its output ports. This switching fabric is completely contained with the router – a network inside of a network router! Output ports. The output port thus performs the reverse data link and physical layer functionality as the input port.
When does a router breaks a packet into smaller parts?
If the packet is too big to travel in between two routing devices, it gets broken into fragments. These fragments look like IP packets in their own right and can traverse the network. They are reassembled when they reach their destination.
What happens, when router receives packet ( s )?
Forwarding can be done by using adjacency tables reside on the route processor or on interface cards that support switching. -> Process switching requires the device CPU to be involved for every forwarding decision. -> Fast switching still uses the CPU for initially packets and to fill cache table in router.
How are packets delivered in the same network?
If the destination host is present in the same network,then the packet is delivered directly to destination host. If the destination host is present in different network then the packet is delivered to the default gateway first which in turn delivers the packet to the destination host.
How is a packet passed through the bridge host table?
Run packet through the bridge host table to make a forwarding decision. A packet where the destination MAC address matches with the bridge MAC address will be passed to the bridge input chain.
Which is the destination address of a packet?
Typically, a packet only has a destination address for a single computer, which tells the routers where to send the data. However, one can use a broadcast address ( https://en.wikipedia.org/wiki/Broadcast_address) which asks the routers to send to everyone within a certain part of the network.