Q 32 from CCNa-801 practice test #1.

babadu

Hello Everyone,

Please help me clarify, If split horizon used only by distance vector routing protocols, what happen when we have hub and spokes frame relay with EIGRP or OSPF configured between the routers? If I recal correctly, I remember reading something about split horizon issues with this type of network. I know I am wrong about sending update immediately

please help.

32. Which of the following are true concerning Split Horizon?
a. Is used only by distance vector routing protocols.
b. Is used only by link-state routing protocols.
c. Routing updates received on an interface are not sent out the same interface.
d. Routing updates are sent immediately when new routes are learned rather than waiting on the update timer to expire.


Answer(s): a. Is used only by distance vector routing protocols.
c. Routing updates received on an interface are not sent out the same interface.
 
Your Answer(s):  c. Routing updates received on an interface are not sent out the same interface.
d. Routing updates are sent immediately when new routes are learned rather than waiting on the update timer to expire.

 



Explanation: 
Split horizon is a mechanism to prevent loops and is used only by distance vector protocols.

Netstudent

http://www.techexams.net/forums/viewtopic.php?t=24958

here is a post about frame-relay and split-horizon. EIGRP will still use splithorizon but OSPF will not.

babadu

Thank you for the link.


In that case split horizon is not only used by distance vector routing protocols.

Stotic

From my understanding, the Split Horizon concept is built into the linkstate algorithm rather then being considered an extra feature like it is with RIP and IGRP.

As per Cisco Press ICND: "OSPF, as a link-state routing protocol, does not need to use any of the distance vector loop-avoidance features. Loop avoidance is effectively built into the routing protocol."