Các giới hạn của các giao thức định tuyến nội IGP

[dangquangminh]

IGP Limitations
Some Limitation you will need to remember when you Choose the right IGP for your Network.

Hop Count :

• RIP has a limit of 15 hops. A RIP network that spans more than 15 hops (15 routers) is considered unreachable.
• Same with EIGRP most any current 12.X version of IOS has a maximum of 255 hops for EIGRP.
• With OSPF, there is no limitation on the hop count.
• Since we talk about RIP, Unfortunately the basic RIP algorithm is rather slow to achieve convergence. It takes a long time for all routers to get the same information, and in particular, it takes a long time for information about topology changes to propagate.

Cisco Routers Only :

• If you have routers from more than one vendor , EIGRP will not be the Right choise since it works only in Cisco Routers
• but my advice change all routers to same Vendor and i recommand Cisco for Routers Products then you can use EIGRP unique benefits like supporting multiple Network layer protocols: IP, IPX, and AppleTalk. also EIGRP is the only Routing protocol working with Concept feasible successors ( second best route as backup).
• Lets remind our selfs that if a network has reached the point where it includes 500 routers, EIGRP may stop working well without a structured hierarchy.
• EIGRP has some Limitation for DMVPN
• Finally There are no limitations on the number of neighbors that EIGRP can support. The actual number of supported neighbors depends on the

capability of the device Hardware Resouces avaialble.

OSPF Limitation :

• no router should be in more than three areas
• no area should contain mor ethan 50 routers
• no router should have mor ethan 60 neighbors
• router can be DR for area and BDR for another area

(Source Yasser Auda, CCIE)