Exam 300-420 topic 1 question 191 discussion

Option C is not the best choice because it involves requesting a full internet routing table and a default route from the ISP. While it does provide flexibility to add prefixes in the future, it also consumes more resources on the customer's router due to the need to process and store the full internet routing table. This may not be necessary if the customer only requires specific prefixes and a default route. Option A, on the other hand, allows the engineer to request a limited internet routing table and a default route, which consumes fewer resources on the customer's router. Additionally, it provides the needed flexibility to add more prefixes in the future without waiting for the ISP's two-week change process, as the engineer can adjust the access list to permit new prefixes as needed.

inbound filter + prefix list correct. anychange on the prefix list, engineer only need to update the preifx list and restart the BGP peer to the ISP. soft-reconfiguration inbound could be used to reduce down time of reset BGP peer, but it require lots of memory and in this case, connection to ISP and tons of route learnt will not be apporitated.

Shouldn't this be Answer: C? "However, the solution must provide the flexibility to add prefixes in the future at short notice." We ask for everything from the ISP + filter the specific routes we need -> And later on if we want more routes we just include them in the filter and boom, we can have any route in 5 minutes (But if we go with Answer D, we would need to contact the ISP every time, we would want them to modify their "outbound filter" to provide us more routes etc...) and that would take alot of time