Cisco Updated 350-501 Exam Questions and Answers by buddy

The ttl-security hops 2 command sets the accepted Time to Live (TTL) value for BGP packets received from a neighbor. It is used to protect against BGP session hijacking by ensuring that BGP packets come from an expected number of router hops away. In this case, the command specifies that BGP packets from neighbor 2.2.2.2 must have a TTL of at least 253, which means they can only be 1 hop away (255 - 2 = 253) to be accepted.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) training material1.

The configuration in Option C uses a route policy that checks if the MED is equal to 30 and then sets the local-preference to 70. This aligns with the requirement to prioritize routes with a MED of 30 by assigning them a higher local-preference value, which influences the BGP path selection process in favor of these routes.

References := The Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course provides insights into configuring route policies for BGP, which includes setting local-preference based on MED values

The RPL script in the image is used to filter BGP routes based on the AS path. The script includes a condition that checks if the AS path contains ‘7077’ using a regular expression (ios-regex ‘777$’). If this condition is met, the route is passed; otherwise, it would be denied by default. Therefore, this script allows routes from AS 7077 and denies others.

References := For specific references, please consult the Implementing and Operating Cisco Service Provider Network Core Technologies source book or study guide, as I am unable to provide direct links or access content from external websites.