About Me
MikroTik Certified Internetworking Engineer (MTCINE)
1 Introduction to Networking
1-1 Basic Networking Concepts
1-2 OSI Model
1-3 TCPIP Model
1-4 Network Devices
1-5 Network Topologies
2 MikroTik RouterOS Basics
2-1 Introduction to RouterOS
2-2 RouterOS Interface
2-3 Basic Configuration
2-4 User Management
2-5 System Logging
3 IP Addressing and Subnetting
3-1 IPv4 Addressing
3-2 Subnetting
3-3 IPv6 Addressing
3-4 IPv6 Subnetting
3-5 NAT and PAT
4 Routing
4-1 Static Routing
4-2 Dynamic Routing Protocols
4-3 OSPF
4-4 BGP
4-5 EIGRP
5 Wireless Networking
5-1 Wireless Basics
5-2 Wireless Security
5-3 Wireless Configuration
5-4 Wireless Bridging
5-5 Wireless Repeaters
6 VPN Technologies
6-1 VPN Basics
6-2 IPsec VPN
6-3 OpenVPN
6-4 L2TPPPTP
6-5 SSL VPN
7 Quality of Service (QoS)
7-1 QoS Basics
7-2 Traffic Shaping
7-3 Policing
7-4 Prioritization
7-5 Queue Types
8 Firewall and Security
8-1 Firewall Basics
8-2 Firewall Rules
8-3 NAT Rules
8-4 Filtering Rules
8-5 Hotspot and Captive Portal
9 Advanced Topics
9-1 VLANs
9-2 MPLS
9-3 High Availability
9-4 Load Balancing
9-5 Monitoring and Troubleshooting
4.4 BGP Explained

4.4 BGP Explained

Key Concepts

1. BGP Overview

Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information among autonomous systems (AS) on the Internet. BGP is the protocol that enables the Internet to function by allowing different networks to communicate with each other.

Example: Think of BGP as the postal service for the Internet. Just as the postal service ensures that mail reaches its destination across different cities and countries, BGP ensures that data packets reach their destination across different networks.

2. BGP Peering

BGP peering refers to the establishment of a relationship between two BGP routers to exchange routing information. Peering can be either external (eBGP) between different ASes or internal (iBGP) within the same AS. Peering relationships are typically established over TCP port 179.

Example: Consider BGP peering as a handshake between two network operators. Just as two people shake hands to establish a connection, two BGP routers establish a peering relationship to exchange routing information.

3. BGP Path Attributes

BGP path attributes are parameters that describe the characteristics of a route. These attributes help in determining the best path for a route. Common path attributes include AS_PATH, ORIGIN, NEXT_HOP, and LOCAL_PREF.

Example: Think of BGP path attributes as labels on a package that provide information about its origin, destination, and handling instructions. Just as labels help in sorting and delivering packages, path attributes help in selecting the best route for data packets.

4. BGP Route Selection

BGP route selection is the process by which a BGP router chooses the best path for a route based on a set of rules and path attributes. The router evaluates multiple routes and selects the one with the highest preference according to the BGP decision process.

Example: Consider BGP route selection as a decision-making process for choosing the best route to a destination. Just as a traveler might choose the fastest or most scenic route, a BGP router selects the best route based on various criteria.

5. BGP Communities

BGP communities are a way to group routes and apply common policies to them. Communities are tags that can be attached to BGP routes to influence how they are handled by neighboring routers. Communities can be used to implement routing policies, such as limiting the propagation of certain routes.

Example: Think of BGP communities as membership groups in a club. Just as members of a club share common interests and benefits, routes with the same community tag share common routing policies.

© 2024 Ahmed Baheeg Khorshid. All rights reserved.