350-060 Question #72: Real Exam Question with Answer & Explanation

A service provider upgraded its core routers to CRS-1. The service provider connects the CRS-1 to an internal network via CRS-1 management ports. This internal network is configured with private IP addresses. All SSH access from a service provider workstation that is incoming to the management ports of the CRS-1 routers was tested and was found to be working properly. The routers were configured for AAA by using the Cisco Secure Access Control Server, and AAA was working as desired. Furthermore, SNMP traffic used the inband 10-Gigabit Ethernet ports, and all SNMP functionality was properly configured and tested prior to the rollout. After CRS-1 routers were placed in production, a need arose to engage Cisco TAC to perform troubleshooting and diagnosis on the routers. It was noted that while all service provider operations staff could access the routers from the private IP- based management network, Cisco TAC could not access the router because its connection was coming in on the inband 10-Gigabit Ethernet ports. The VTY line ACLs were configured to allow the Cisco TAC source IP address, but that did not fix the problem. What is a possible cause for the lack of connectivity? (Choose one.)