Which layer eigrp works

At Layer 2, switches within a building and even across a campus will use the Spanning Tree Protocol STP and its many variants to create a redundant switch fabric that distributes traffic across multiple links and handles device and link failure. In the absence of a control protocol such as STP, a LAN with a loop in it can flood itself with traffic by continually sending the same packets around the loop. With STP in place, a network manager can design a network with some redundancy — a loop — without the network melting down the first time a broadcast frame is sent.

STP uses timers to learn network topology. During the learning phase and any topology change, the network can block some or all traffic over a link. The big change: shorter timers and a network convergence time reduced from minutes to a few seconds. The key benefit of MSTP is that different VLANs can use different links across the network, allowing redundant links to be more fully utilized to speed traffic whenever possible.

For now, network managers should plan on MSTP for at least the next five years. This is a typical monday morning problem. We can use show ip eigrp neighbors and see that there are no neighbors. After changing the AS number life is good. If you look at the output of show ip protocols you can see that the network has been advertised correctly. If you look closely on R2 you can see that we have a passive interface. If you like to keep on reading, Become a Member Now! Here is why:.

Am I correct in saying that you can use the neighbor command with sub-interfaces and have some of those sub-interfaces using the neighbor command with the others establishing a neighborship via normal means i. From an article I read from Kevin Wallace, where three routers were connected via a switch and using physical interfaces , R1 and R2 initially established a dynamic neighborship, but then when R3 was introduced and a static neighbor was configured between R2 and R3, it broke the dynamic neighborship between R1 and R2.

Yes, it is possible to use the neighbor command with sub-interfaces. Each sub-interface, just like the physical interfaces, can be configured to either automatically achieve neighbor relationship with an EIGRP neighbor, or achieve it manually via explicitly configuring the IP of the neighbor. Now in the example that you state, the situation is different. Here you have three routers connected to the same subnet. When you configure a static neighbor adj. Hello Liz Sir! In no event shall Author be liable for any damages whatsoever including, without limitation, damages for loss of use, data or profit arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Routing protocols are not layer 3 or 4, as they support layer 3 but are not layer 3. I recall? Consider static routing, what's that? So are network engineers layer 3 too? IP layer 3 accepts a packet, looks at its destination address, and then makes a routing decision for that packet.