Exam 300-410 topic 1 question 24 discussion

We=weight love=local preference oranges= originated locally >remotely as= as path oranges= origin code (IGP, EGP, incomplete?) mean= MED (metric) pure= eBGP > iBGP learned refreshment= highest RID.

Should be a, as weight values aren't shared between routers, but local preference is, correct?

So where's the another neighbor statement?

D is correct

The AS of the router is 100, the neighbor 10.22.22.1 is AS 1, then the route announce to this must be eBGP route, and it must have a 1 prepend in it. The patten ^690$ shall match any path list that start with 690 and end with 690, so it should not set any weight nor local preference on that.. while local preference does not have effect, the weight should make it prefer to other, but it should not be advertised by other but rather have another setting to set the WEIGHT higher..

show ip bgp regexp ^100$ match the direct peering learned routes from as 100 ^$ - match locally originated routes only D makes sense

Not only is the situation described disgustingly, but also regexp will not match prefixes from AS1. We do not see the settings of "another neighbors". The question is obviously on the knowledge of path selection, but it is not clear where to apply this knowledge here ...

The correct answer is: D

Why does the neighbor have AS1, and we are waiting for updates from AS690?

correct answer is not in options - router is sending traffic elsewhere, because it can never receive update matching as-path statement ^690$ from neighbor in AS 1. So it must receive update from other neighbors and that's why it sends it the other way. But when following "excluding wrong options" approach, D remains the last.

Just D seems to be correct, because LOCAL-PREFERENCE is used for choosing best path between different routers.

D is correct because we are only dealing with one router here, with its different bgp route statements.

Attributes are processed in the order : 1. Prefer the highest weight 2. Prefer the highest local preference D is ok

I tested in GNS3 and router is choosing weight first between 2 eBGP neighbors for the same route.

weight comes before local-pref in BGP routing decisional process

D is correct

We all know Weight is local to each router, right? So if one of the neighbors has already been set to a weight of 200 (which one has in this config), then the only reason a third neighbor would be used is if weight of a third neighbor was higher. Because weight is more preferred than Local Pref, it won't matter what you set Local Pref to on any neighbor, the chosen one will always be the weight=200 UNLESS someone else has a higher weight. And don't forget, we're only looking at this one router, not a set of routers in an AS.