Free Juniper JN0-683 Actual Exam Questions - Question 3 Discussion
Referring to the exhibit, why is the active source field blank for the entry that uses the
00:0c:29:e8:b7:39 MAC address?
This one’s tricky, but I’m going with C. Locally connected hosts usually don’t have an active source IP because they’re directly attached, so the field would be blank. That seems cleaner than B, since an ARP failure typically wouldn’t leave the MAC known without any IP info at all—it’d probably just not show the entry. Plus, multicast EVPN routes usually have different markers, so D feels less likely here.
B/D? The blank active source could mean the system knows the MAC but can’t find the IP, which fits B. But if this were a multicast EVPN route, that might also explain why no IP shows up since multicast entries sometimes don’t have an associated source IP. I’m not sure if the exhibit clarifies whether this is a multicast or unicast route though, which makes it tough to rule out D. So it’s either a failed ARP or multicast-related missing IP info.
It’s C because locally connected hosts usually show no active source IP.
Option B makes sense too because if the ARP lookup fails, the system wouldn’t have an active source to list, leaving that field blank. That fits a scenario where the MAC is known but IP resolution isn't complete.
It’s A. If the EVPN route didn’t have a valid next hop, the active source would be blank since the device can’t resolve where to forward packets for that MAC. That fits this scenario better than local connection.
D imo – multicast EVPN routes often show blank active source fields.
Looks like the answer is C. The blank active source means the host is directly connected to leaf1, so no active source needed.