Javatpoint Logo
Javatpoint Logo

BGP vs. EIGRP: What's the Difference?

Two critical internet routing protocols, Border Gateway Protocol (BGP) and Enhanced Interior Gateway Routing Protocol (EIGRP), play significant roles in network connectivity.

Distinguishing between them is straightforward: EIGRP facilitates connections within networks confined to an Autonomous System (AS), while BGP enables connections between different ASes, thereby defining broader network structures. An AS typically comprises multiple separate networks needing integration to access the internet. BGP focuses on routing to external networks, such as the internet, whereas EIGRP manages internal data routing within networks. Consequently, BGP is utilized for interactions with external ASes and the internet, while EIGRP is employed for routing information within networks.

BGP vs. EIGRP: What's the Difference?

Figure 1. The autonomous devices in this illustration communicate with outside ASes and the internet using BGP and internal ASes using EIGRP.

The possible operations of BGP and EIGRP in a network setup are shown in the Figure 1.

Border Gateway Protocol (BGP)

BGP is a popular and well-known protocol. Networks are usually constructed in a structure called a mesh network, meaning all entities link to one another, as seen in Figure 2. It communicates with various routers via TCP port 179.

BGP vs. EIGRP: What's the Difference?

When figuring out ways to connect to certain IP ranges inside that AS, each autonomous network, or AS, communicates routing information with another network.

In contrast to EIGRP, BGP is an external gateway protocol that is used for routing across distinct networks without administrative supervision. The internet uses BGP as its routing protocol, which connects an AS to an ISP so that the latter may access the internet.

The fact that BGP is a protocol for flexible routing is a significant feature. This indicates that it can provide load balancing across the internet lines and numerous internet connections with urgent backup capabilities. Since the loss of a major ISP connection immediately initiates failover to an alternative link to retain the best possible path to the internet, the failover capability is crucial for disaster recovery.

In actuality, a protocol for transport link is established by systems wishing to interact. Subsequently, both systems establish the connection's parameters by exchanging and verifying messages. Through a BGP routing table, they communicate with each other to establish and verify the connection settings.

While interactions with external ASes and the internet utilize BGP, data routing inside networks uses the EIGRP protocol.

BGP attempts to maintain the link after it has been developed, regardless of the routing table changes. The whole BGP routing table is used in the first data flow. When the routing tables are updated, incremental changes are transmitted. When an anomalous situation arises, notifications of errors are delivered. Although BGP links inside an AS are commonly referred to as links within it, BGP links with additional networks are known as external connections.

The Internet Engineering Task Force (IETF) created BGP as a standard protocol. It was first implemented in the early 1990s and has subsequently been modified into later versions, such as BGP-3 and BGP-4.

Enhanced Interior Gateway Routing Protocol (EIGRP):

When EIGRP was first created by Cisco in the 1990s, it could only be used in Cisco-branded equipment. Cisco submitted EIGRP as a draft protocol to the IETF in 2013 for evaluation and eventual adoption as a formal standard. It remains in draft form at the IETF as of right now.

EIGRP is an internal gateway system that, in contrast to BGP, continuously distributes information traffic over an internet connection that is entirely managed by an organization, such as a government or commercial network. Since it incorporates elements of the two following protocol categories, EIGRP is regarded as a hybrid protocol:

Distance vector routing, whereby routers communicate with neighboring routers on a frequent basis on modifications to the network's structure; and link-state routing, which notifies every router about the topology of the whole network using messages.

For university network routing, network managers often use EIGRP for both large and tiny applications. Due to its capacity to combine the requirements of rapidity, productivity, adaptability to growth, and simplicity of usage, EIGRP is also widely used in private networks.

The diffusing update method, which is used by EIGRP, carries out the following tasks:

  • Finds the most affordable connections to other reachable network locations.
  • Guarantees that, even when network topology changes, every connection remains consistently loop-free.
  • Guarantees that, in order to preserve loop integrity, every router impacted by a change topology creates a new optimal path.


BGP and EIGRP offer quick, easy, and affordable data routing for the appropriate applications. EIGRP is best suited for smaller network infrastructures that link to greater networks via BGP, whereas BGP is best suited for larger networks connecting to other large networks.

Youtube For Videos Join Our Youtube Channel: Join Now


Help Others, Please Share

facebook twitter pinterest

Learn Latest Tutorials


Trending Technologies

B.Tech / MCA