Free Cisco 350-501 SPCOR Actual Exam Questions - Question 5 Discussion
Refer to the exhibit. 
An engineer is trying to implement BGP configuration on a router Which configuration error prevents the ASBR from establishing a BGP neighborship to a directly connected BGP speaker?
B/C? The VPNv4 family (C) shouldn't really cause a session to fail unless there's some misconfiguration with route targets or something else. But having the IPv4 address family directly under neighbor config in IOS XR can indeed cause issues if the syntax isn't supported or needed, so B seems like a more straightforward reason for failure here. Also, D is out since TCP params are usually defaulted and A seems unrelated to the direct neighborship issue. So between B and C, B feels like the more plausible blocker for establishing the session.
Makes sense, the extra IPv4 family config under neighbor should be removed for eBGP on IOS XR B.
It’s C because VPNv4 and IPv4 address families can conflict in BGP sessions.
Option B, the IPv4 address family under neighbor config causes the session to fail.
B tbh, having IPv4 address family under neighbor config on IOS XR often causes issues. Removing it fixes the eBGP neighborship problem here.