Quick Answer: Why Do We Use BGP Instead Of OSPF?

Why do we need BGP?

Border Gateway Protocol (BGP) is used to Exchange routing information for the internet and is the protocol used between ISP which are different ASes.

The protocol can connect together any internetwork of autonomous system using an arbitrary topology..

Why BGP is used in MPLS?

BGP is a protocol used to carry external routing information such as customers’ routing information or the internet routing information. … The MPLS tunneling mechanism allows core routers to forward packets using labels only without the need to look up their destinations in IP routing tables.

Why is BGP slow protocol?

Keep in mind, though, BGP is a “slow to converge” protocol. Routing changes on the Internet occur all the time. If BGP had to react to every change, it would flood the Internet with routing updates that could slow traffic all over the globe. … This is why BGP is seldom used as an internal routing protocol.

Which is better OSPF or BGP?

BGP is more flexible and scalable than OSPF and used on a larger network, unlike OSPF. The primary objective of the OSPF is to determine the best route, i.e., fastest. Conversely BGP emphasizes on determining the best path. OSPF uses link state routing while BGP uses path vector routing.

Why OSPF is not used as EGP?

The IETF working group for OSPF was, in fact, started in 1988, while the original version of BGP, called EGP, was originally specified by Eric Rosen in 1982, some 6 years earlier. The short answer might be, then, that OSPF was not considered because OSPF had not been invented yet.

Is OSPF still used?

OSPF is one choice for a routing protocol, but it is an industry standard, and just about every business-grade router supports it. It is also very well understood by most network engineers, and fairly simple to configure.

Why we use OSPF?

The OSPF protocol is a link-state routing protocol, which means that the routers exchange topology information with their nearest neighbors. … The main advantage of a link state routing protocol like OSPF is that the complete knowledge of topology allows routers to calculate routes that satisfy particular criteria.

Is BGP Layer 3 or 4?

BGP is a Layer 4 protocol that sits on top of TCP. It is much simpler than OSPF, because it doesn’t have to worry about the things TCP will handle. Peers that have been manually configured to exchange routing information will form a TCP connection and begin speaking BGP.

What is a BGP AS number?

A unique ASN is allocated to each AS for use in BGP routing. … ASNs are important because the ASN uniquely identifies each network on the Internet. Until 2007, AS numbers were defined as 16-bit integers, which allowed for a maximum of 65,536 assignments.

How does BGP work with OSPF?

If you configure the redistribution of OSPF into BGP without keywords, only OSPF intra-area and inter-area routes are redistributed into BGP, by default. You can use the internal keyword along with the redistribute command under router bgp to redistribute OSPF intra- and inter-area routes.

Is OSPF better than Eigrp?

OSPF scales better than EIGRP because EIGRP is more complex in very large scale networks while troubleshooting. Compared to EIGRP, OSPF is better to use on WAN since most of the service providers support it. OSPF have already been running in internal environments as an IGP (Interior Gateway Protocol).

IS IS protocol vs OSPF?

IS-IS runs on the data link layer, whereas OSPF runs on the network layer. OSPF supports virtual link, whereas IS-IS does not support. OSPF elects a DR and BDR, whereas IS-IS elects only a single DR called DIS.

Does OSPF uses TCP or UDP?

OSPF messages ride directly inside of IP packets as IP protocol number 89. Because OSPF does not use UDP or TCP, the OSPF protocol is fairly elaborate and must reproduce many of the features of a transport protocol to move OSPF messages between routers.

Why is BGP scalable?

Make the input queues big enough to hold all of the TCP Acks that would be generated if all of your peers where to Ack their entire window size of data at the exact same time. The result is that BGP will converge much faster because we are no longer dropping tons of packet on the interface input queues.

Which layer is OSPF?

TransportThe OSI Seven Layer ModelLevelNameExamples1PhysicalDSL, Ethernet, ISDN, RS-2322Data LinkEthernet, PPP, SLIP, HDLC3NetworkIP, IPX, DDP4TransportTCP, UDP, OSPF, BGP3 more rows