CCIE CCIE Enterprise Infrastructure 3

Question 1

Which Cisco feature enables automatic failover of Layer 3 gateway redundancy using virtual IP and MAC addresses?

Accepted Answer

All of the above provide gateway redundancy

Answer

HSRP, VRRP, and GLBP all provide first-hop redundancy using virtual IPs; GLBP additionally provides load balancing across multiple routers.

Question 2

In MPLS, what is the label imposed at the ingress PE router called?

Accepted Answer

Transport label

Answer

The transport (outer) label is imposed at the ingress PE and used by the MPLS core (P routers) for forwarding decisions.

Question 3

What is Penultimate Hop Popping (PHP) in MPLS?

Accepted Answer

Removing the transport label at the second-to-last hop

Answer

PHP removes the outer transport label at the penultimate (second-to-last) hop, reducing processing at the egress PE router.

Question 4

Which 802.1Q feature allows traffic from multiple VLANs to traverse a single physical link between switches?

Accepted Answer

Trunk port

Answer

Trunk ports use 802.1Q encapsulation to tag frames with VLAN IDs, allowing multiple VLANs to traverse a single inter-switch link.

Question 5

In OSPF, what mechanism prevents routing loops by ensuring non-backbone areas communicate only through Area 0?

Accepted Answer

Backbone requirement

Answer

OSPF requires all non-backbone areas to connect to Area 0 (backbone), which prevents routing loops in multi-area OSPF designs.

CCIE - Cisco Certified Internetwork Expert Practice Test