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Why do different IP networks need to be assigned to different ports of a router?
If they’re in the same network, they send directly; otherwise, they send to a router whose job is to get the message closer to the destination. So if a device is connected to multiple networks, it needs an address on each of those networks so it can be reached by devices on that network.
Does every interface have an IP address?
Each network interface must have its own unique IP address. The IP address that you give to a host is assigned to its network interface, sometimes referred to as the primary network interface. The network interface might have a device name, such as le0 or smc0 , device names for two commonly used Ethernet interfaces.
Why are IP addresses given to each interface?
Likewise, a host can have many network connections and accordingly, IP addresses. Different interfaces often have different functions, so it’s important to distinguish between them (e.g. internal console, public services, iSCSI).
How are IP addresses used in a routing system?
IP addresses include routing information. An IP address is split up into two components, the network number and the host number, based on an assigned prefix length (which was originally expressed as a network mask, and this is still often how it’s implemented internally in network stacks).
Can a device have the same IP address as a computer?
In the case of IPv6 (using “link-local” addresses) a computer can have the same (link-local) IP address in two different networks – and therefore two network cards can have the same IP address! A device that has an IP address exists within a network.
How to assign an IP address to a device?
But you can use “IP unnumbered”, and not associate any IP addresses to those links. Now, you assign an IP to the device’s loopback interface (any interface really, but loopback is the easiest one for this purpose), and you use a dynamic routing protocol (IS-IS, OSPF, EIGRP…).