Routers and Gateways are 2 terms widely used in Network and Security domains. Both terminologies have a thin line of differentiation, with some of functionalities overlapping , rather many times a single device (maybe Router) performs the functionality of both a Router and Gateway.
A Router is a Network device that forwards packets from one network to another when a packet comes in through one port, the router reads the address information on the packet and determines the right destination, then uses routing table or routing policy to direct the packet to the next network or next hop. A router is a device that is capable of sending and receiving data packets between computer networks, also creating an overlay network.
A Gateway, on the other hand, joins dissimilar systems. Gateway it is defined as a network entity that allows a network to interface with another network with different protocols. Gateways acts as a network point that acts as an entrance to another network. The gateway can also allow the network to connect the computer to the internet.
Below table will help clearly differentiate between both Router and Gateway –
|Terminology||Network device that forwards packets from one network to another.Based on internal routing tables, routers read each incoming packet and decide how to forward it. Routers work at the network layer (layer 3) of the protocol||Device that converts one protocol or format to another. A network gateway converts packets from one protocol to another. The gateway functions as an entry/exit point to the network.|
|Primary Goal||Route traffic from one network to other.||Translate from one protocol to other|
|Feature support||Routers provide additional features like DHCP server, NAT, Static Routing, and Wireless Networking/IPv6 address , Mac address||Protocol conversion like VoIP to PSTN or Network Access Control etc.|
|Dynamic Routing||Supported||Not supported|
|Hosted on||Dedicated Appliance (Router hardware)||Dedicated/Virtual Appliance or physical Server|
|Related terms||Internet Router, Wireless Router||Proxy server, Gateway Router, Voice Gateway|
|OSI layer||Works on Layer 3 and 4||Works upto Layer 5|
|Working principle||Works by installing routing information for various networks and routes traffic based on destination address||Works by differentiating what is inside network and what is outside network|