The alert shown in the exhibit is designed to detect which of the following network...

As shown inExhibit 4.1-1(image_6e19fb.png), the alert rule is configured for the BGP layer with the name "AS origin AS 1234". The critical logic is defined in theAlert Conditionssection, which specifies: BGP Origin meets all of: ASN not in 1234.

This specific configuration is the standard method used in ThousandEyes to detectBGP hijacking(Option C). BGP hijacking occurs when an unauthorized Autonomous System (AS) announces a network prefix that it does not own, effectively stealing the traffic meant for the legitimate owner. By setting an alert that triggers when a monitored prefix is seen originating from an Autonomous System Number (ASN) that isnotthe expected authorized ASN (in this case, AS 1234), ThousandEyes provides immediate notification of a routing takeover.

Identifying this via BGP Origin alerts is superior to simple connectivity checks because it catches the issue at the routing control plane.

DNS Issues (Options B and D):These involve the translation of names to IPs and would be detected via DNS-specific tests rather than BGP Origin checks.

Route Poisoning (Option A):This is a generic term often referring to the manipulation of distance-vector protocol metrics to make a route unreachable; while related to routing, BGP Origin checks are the specific tool for detecting external prefix hijacks.

By monitoring the ASN origin, network engineers can quickly distinguish between a local ISP outage and a global security event where their traffic is being misdirected to an illegitimate network.