Routing

A networking device that is used to route traffic between different subnets or between an internal and external network. Routers separate broadcast domains and provide additional efficiency and security to networks.

A device, such as a router, that operates at the network layer of the OSI model and is used to separate and break apart broadcast domains into smaller portions.

A layer three switch that can perform both layer two forwarding and layer three routing functions.

The router that is used as a default destination for network traffic when the destination MAC address is not known.

A layer two piece of information that is used to transmit data between devices within a local area network.

A layer three packet that contains data and is used to transmit data between devices across different networks.

A table kept by a router that contains information about different routes, including the destination network, the router to be used, the port to be used, and the cost of the route.

The part of an IP address that specifies the network portion of the address. The longer the prefix, the more specific the network is.

A method of representing IP addresses and their associated routing prefixes. The longer the CIDR notation, the more specific the network is.

A route learned by a physical connection between two routers.

Routes that are established when routers are directly connected to each other or to other devices. They are automatically learned and allow routers to know how to reach networks that are directly connected to them.

Routes that are manually configured by an administrator. They allow routers to know how to reach networks that are not directly connected to them by specifying the next hop router.

A special static route that is configured as 0.0.0.0/0. It acts as a default gateway for the router, instructing it to send any traffic for which it doesn't have a specific route to the next hop specified in the default route.

A method of automatically learning and exchanging routing information between routers using dynamic routing protocols. It allows routers to dynamically update their routing tables based on network changes.

Protocols used by routers to exchange routing information and dynamically update their routing tables. These protocols include OSPF, RIP, and EIGRP.

A technique used to prevent routing loops by preventing a route learned on one interface from being advertised back out that same interface.

A technique used to prevent routing loops by causing a route received on one interface to be advertised back out that same interface with a high cost, making it undesirable to use.

A situation where routers continuously forward packets in a circular manner, causing them to be stuck in the network and leading to network congestion and inefficiency.

Protocols that allow routers to exchange information about routes they know.

Routing protocols that operate within a network or autonomous system.

Routing protocols that operate between autonomous systems on exterior networks.

A characteristic of every routing protocol that determines how routes are received, advertised, and provided to other routers.

A routing method that considers the number of routers a route passes through.

The time it takes for all routers to update their routing tables in response to a topology change.

A network where all routers have the same information in their routing tables.

A timer that reduces the frequency of routing table updates to speed up convergence time.

The number of routers a packet must pass through to reach its destination.

A routing method that considers the cost and speed of connections to determine the best route.

The bandwidth available on a connection.

An interior gateway protocol that uses distance vector routing and hop count to determine routes.

An interior gateway protocol that uses link state routing and cost to determine routes.

An interior gateway protocol that functions similarly to OSPF but has less widespread adoption.

A routing protocol that combines distance vector and link state routing methods.

An advanced distance vector protocol that uses both bandwidth and delay to make it a hybrid of the distance and link state protocols.

A protocol that can only be used with specific products, in this case, EIGRP can only be used with Cisco products.

An external gateway protocol used as the backbone of the internet, which uses a path vector to determine the number of autonomous system hops.

A value used by routers to determine the believability of a route, with lower values being more believable.

Factors used by routing protocols to determine the best route, including hop count, bandwidth, delay, cost, and reliability.

A method used to translate private IP addresses into public IP addresses for routing over the internet.

A type of NAT that dynamically assigns public IP addresses from a pool of addresses for one-to-one translation.

A variation of NAT that translates multiple private IP addresses to a single public IP address by using different port numbers.

A method of NAT where the router dynamically assigns a public IP address to a private IP address when it is needed for internet access.

A method of NAT where a private IP address is manually assigned to a public IP address on a one-to-one basis.

A method of NAT that allows multiple private IP addresses to share a single public IP address by using different port numbers to keep track of the connections.

The private IP address that references an inside device.

The public IP address that references an inside device.

The private IP address that is being referenced from the outside.

The public IP address that is referencing an outside device.

A protocol used by clients and routers to manage multicast group membership.

The first version of IGMP where clients have to periodically confirm their membership in a multicast group.

An improved version of IGMP where clients can send leave messages to exit a multicast group.

The latest version of IGMP that allows clients to request multicast from specific servers and supports source-specific multicast.

A protocol that allows multicast traffic to be routed between multicast-enabled routers.

Dense Mode in PIM which uses periodic flood and prune behavior to form an optimal distribution tree across routers.

Sparse Mode in PIM which initially uses a shared distribution tree and then finds the best tree over time.

A process in PIM-DM where all routers in the network receive all multicast information and then non-optimal routes are pruned off.

The quickest and easiest path between the source router and the last hop router in PIM-DM.

The initial tree used in PIM-SM to send multicast messages from the first router to the last hop router.

A point in PIM-SM where multicast messages are sent before reaching the last hop router.

The optimal tree in PIM-SM after switching from the shared distribution tree.

A path in PIM-SM that is not the most optimal but still functional.

The network capacity and bandwidth used in transmitting multicast messages.

The decision between starting with an optimal path but flooding the network (PIM-DM) or waiting for optimal and using fewer resources (PIM-SM).