Free Juniper JN0-105 Actual Exam Questions - Question 7 Discussion

B/C? Switches can cause loops if spanning-tree isn’t running, so B makes sense. And they always flood broadcasts to all ports except the source, so C fits too. A and D don’t really match how switches work.

C/D? D is definitely wrong because switches do learn MAC addresses to build their tables. A is tricky—each switch port creates its own collision domain, not one single domain. So A can be eliminated. That leaves B and C, and even without explicitly saying spanning-tree is disabled, B still holds since loops are a known risk in Layer 2 switches without loop prevention. So I’d go with B and C.

It’s C for sure because switches do flood broadcast traffic across all ports except the source. I’d also pick B since without spanning-tree or any loop prevention, switches can cause traffic loops. The question doesn’t say spanning-tree is on, so it’s safer to assume B is valid here. A and D are definitely wrong—switches separate collision domains per port, and they do learn MAC addresses to forward frames properly.

B (traffic loops can happen without spanning-tree).

B and C are right. Switches can have traffic loops and they flood broadcast traffic. A is wrong because switches create separate collision domains per port. D is also wrong since switches learn MAC addresses to forward frames.