Thanks all. It's clear now. I didn't reply earlier, because I was studying for the BSCI/routing exam which I passed Thursday. The exam wasn't easy, but it wasn't that difficult either. I had questions about all exam topics. I had to guess two questions, because I really didn't know the answer by heart: some things I just refuse to learn, because I know where to find the answer, but unfortunately Cisco is testing them. Moreover, there were several questions that I understood and I knew the answer of, but I really didn't know which option Cisco wanted me to pick here... I think they take some questions somewhere from their course books or documentation and the answer then depends on the issue they are covering in that particular section. You really have to guess then "Do they want to hear this or that" because several answers are possible depending on the context... and the context is not clear from their question...
Remaining questions and simulations were rather straightforward. If you study all topics, this exam shouldn't be a problem. Eric ----- Original Message ----- From: To: "ericbrouwers" Sent: Friday, January 24, 2003 3:21 PM Subject: Re: Why is OSPF E1 route preferred over E2 route? [7:61619] > > Other point of view: > > Maybe using E1 could be better when you have two exit points because you > will use the better cost to the outside world. > > > > > > > "ericbrouwers" @groupstudy.com em 23/01/2003 > 17:51:53 > > Favor responder a "ericbrouwers" > > Enviado Por: [EMAIL PROTECTED] > > > Para: [EMAIL PROTECTED] > cc: > > Assunto: Re: Why is OSPF E1 route preferred over E2 route? [7:61619] > > > Thanks, although I'm not sure I completely understand it now... I will > reread tomorrow. > > Eric > > ----- Original Message ----- > From: "cebuano" > To: "'ericbrouwers'" > Sent: Thursday, January 23, 2003 1:09 AM > Subject: RE: Why is OSPF E1 route preferred over E2 route? [7:61619] > > > > Eric, > > This is relevant only when you have multiple ASBRs advertising the same > > destination into the area. The default Type 5 LSA into the area is E2. > > However, if the router hears both E1 and E2 advertisements, then E1 will > > be preferred. The order from most to least preferred is Intra-area, > > Inter-area, E1, then E2. As far as cost, the least cost path is ALWAYS > > preferred. This is one way of influencing which path is actually chosen > > by changing the type of External LSA that you configure to be advertised > > into the area. > > > > Let me know if you need further clarification. > > Elmer > > BTW - your questions remind me of the same questions I had when I was > > studying for the BSCN exam. > > > > > ----- Original Message ----- > From: "bergenpeak" > To: > Sent: Thursday, January 23, 2003 12:29 AM > Subject: Re: Why is OSPF E1 route preferred over E2 route? [7:61619] > > > > In the docs I've read (and I think this was posted on this list as > > well), one might use E2s when you've got one exit point that is always > > prefered over the other(s). This might happen if you've got 2 ISPs > > and one configured as a backup only. The primary exit point is always > > prefered, regardless of the internal cost to get to it. > > > > E1s are useful when one might want to load share traffic to the exit > > points. Each router computes the internal cost to each exit, and > > takes the path to the closest based on internal cost. > > > > ericbrouwers wrote: > > > > > > Hi, > > > > > > Why is an E1 route preferred over an E2 route for the same destination? > > > > > > The cost of an E1 route is the sum of the external reported cost and > the > > > internal cost used to reach that destination. > > > The cost of an E2 route is always the external cost, irrespective of > the > > > internal cost to reach that route. > > > > > > This implies that the path with the higher cost is preferred.... Is it > > maybe > > > because E1 routes are reflecting the real cost? They are not hiding the > > > internal costs.....But if this is the reasoning behind it, why has > Cisco > > made > > > E2 the default instead of E1???? > > > > > > Anyone an idea? > > > > > > Eric Brouwers > > > > > > By the way, CCNP Routing Exam Certification Guide seems to be wrong on > page > > > 294, chapter 6. The E2 definition is not right: > > > "... > > > The routes discovered by OSPF in this way can have the cost of the path > > > calculated in one of two ways: > > > . E1-The cost of the path to the ASBR is added to the external cost to > the > > > next-hop router outside the AS. > > > . E2-The cost of the path to the ASBR is all that is considered in the > > > calculation. This is the default configuration. This is used when there > is > > > only one router advertising the route and no selection is required. If > both > > > an > > > E1 and an E2 path are offered to the remote network, the E1 path will > be > > > used. > > > ..." Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=62715&t=61619 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
