Cisco routing provides the essential infrastructure for delivering advanced IP services across the broad range of Cisco networking products. It encompasses a suite of IP routing protocols, whether based on IETF standards or Cisco innovations.
Essentially, Cisco routing is how data packets are efficiently forwarded between different networks using Cisco routers and related technologies. It's the core functionality enabling data to travel from its source to its destination across an IP network.
Here's a breakdown of key aspects of Cisco routing:
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IP Routing Protocols: These protocols dictate how routers learn about networks and make decisions on the best paths to forward traffic. Examples include:
- RIP (Routing Information Protocol): An older distance-vector protocol.
- EIGRP (Enhanced Interior Gateway Routing Protocol): A Cisco proprietary enhanced distance-vector protocol.
- OSPF (Open Shortest Path First): A link-state protocol.
- BGP (Border Gateway Protocol): A path-vector protocol used for routing between autonomous systems (often used by ISPs).
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Cisco Routers: These are specialized hardware devices designed to forward data packets efficiently. They examine the destination IP address of each packet and use their routing tables (built using routing protocols) to determine the next hop.
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Routing Tables: These tables contain information about networks and the best path to reach them. Routers use these tables to make forwarding decisions.
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Forwarding Decisions: Based on the routing table, the router determines the optimal path for the data packet to reach its destination and forwards the packet to the next hop router.
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Advanced IP Services: Cisco routing enables the delivery of advanced services, such as:
- Quality of Service (QoS): Prioritizing certain types of traffic.
- VPNs (Virtual Private Networks): Securely connecting networks over the internet.
- Multicast Routing: Efficiently distributing data to multiple recipients.
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Cisco Innovations: Cisco has contributed significantly to routing technology through proprietary protocols (like EIGRP), features, and enhancements that improve performance, security, and scalability.
In summary, Cisco routing is the foundation upon which modern IP networks are built, providing the intelligence and mechanisms necessary for data to traverse networks efficiently and reliably, enabling a multitude of advanced services and applications.
