> > At 07:42 AM 10/12/00, [EMAIL PROTECTED] wrote:
>>
>> >Actually, EIGRP is a hybrid protocol which means it is
>distance vector and link-state.
>>
>> EIGRP is not a link-state protocol. It's an "advanced"
>distance-vector protocol.
>>
>> Regarding the main question, I wouldn't think OSPF would need
>to deal with split horizon, but I can't answer that part for
>sure.
>>
>> Priscilla
>>
>> >Split horizon kills routing loops which can occur in either
>of the 2 so it is indeed available in OSPF. I know this for a
>fact because there is a command to disable it in OSPF: no split-
>horizon ospf, or something like that...
According to RFC 1058,
""Split horizon" is a
scheme for avoiding problems caused by including routes in updates
sent to the gateway from which they were learned. The "simple split
horizon" scheme omits routes learned from one neighbor in updates
sent to that neighbor. "Split horizon with poisoned reverse"
includes such routes in updates, but sets their metrics to infinity."
Split horizon deals with routes. OSPF sends link state announcements,
which are NOT routes.
Split horizon also tends to deal with problems caused by old
information. Both link state and distance vector protocols that use
reliable update know what information is current.
>Enhanced IGRP integrates
>the *capabilities* of link-state protocols into distance-vector
>protocols. It incorporates the Diffusing-Update Algorithm
>(DUAL) developed at SRI International by Dr. J.J. Garcia-Luna-
>Aceves.
JJ has made the point in mailing lists that he had nothing to do with
Cisco's implementation. He is emphatic, however, that it is a point
in the continuing evolution of distance vector routing protocols.
Dino Farinacci and others then at Cisco also are distance vector
proponents. JJ has published work on yet more advanced distance
vector.
Some respected protocol architects argue that there are potential
superiorities of modern distance vector algorithms over link state.
These include more linear scaling of route computation load, and
better tolerance to incorrect updates. This definitely gets into the
research area.
>
>A better explanation of this protocol would likely come from
>its author, who did not call it the DUAL Algorithm. Here is
>what Dr. J.J. Garcia-Luna-Aceves had to say on, "Loop-Free
>Routing Using Diffusing Computations.":
>
_________________________________
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
