Cisco ENCOR IP Services and QoS 3

Question 1

Which field in the IPv4 header is used by DiffServ to carry DSCP markings?

Accepted Answer

ToS (Type of Service) / DSCP field

Answer

The 6-bit DSCP value is carried in the Type of Service (ToS) byte of the IPv4 header (specifically the top 6 bits).

Question 2

What is the primary purpose of HSRP (Hot Standby Router Protocol)?

Accepted Answer

Provide a virtual default gateway with automatic failover for LAN hosts

Answer

HSRP provides a virtual IP and MAC address shared between routers, allowing transparent failover if the active router fails.

Question 3

In NAT, what does PAT (Port Address Translation) allow?

Accepted Answer

Many internal hosts to share a single public IP by using unique source port numbers

Answer

PAT (also called NAT overload) allows many internal hosts to share one public IP by differentiating connections with unique source port numbers.

Question 4

What is the SNMP OID structure based on?

Accepted Answer

A hierarchical tree defined by the Management Information Base (MIB)

Answer

SNMP Object Identifiers (OIDs) are structured as a hierarchical dotted-decimal tree defined by the MIB standard.

Question 5

Which first-hop redundancy protocol is an open standard (not Cisco proprietary)?

Accepted Answer

VRRP

Answer

VRRP (Virtual Router Redundancy Protocol, RFC 5798) is the open-standard equivalent of Cisco's proprietary HSRP.

Cisco ENCOR Practice Test