Selected Answer: C inbound filter + prefix list is correct. any change on the prefix list, engineer only needs to update the preifx list and restart the BGP peer to the ISP. soft-reconfiguration inbound could be used to lower down time of BGP peer reset, but it requires lots of memory and in this case, connection to ISP and tons of route learnt will not be apporitated.

Selected Answer: A Option C is not the best pick because it involves requesting a full internet routing table and a default route from the ISP. While it does give flexibility to add prefixes in the future, it also uses more resources on the customer's router because it has to process and store the full internet routing table. This may not be needed if the customer only needs specific prefixes and a default route. Option A, on the other hand, lets the engineer request a limited internet routing table and a default route, which uses fewer resources on the customer's router. Also, it gives the needed flexibility to add more prefixes in the future without waiting for the ISP's two-week change process, since the engineer can adjust the access list to allow new prefixes as needed.

Selected Answer: C 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 add them in the filter and boom, we can get 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 give us more routes etc...) and that would take a lot of time