IX General Quiz

Last usable host address in subnet 145.82.0.0/15:

• 145.82.0.254

• 145.82.255.254

• 145.83.0.254

• 145.83.255.254

VRF functionality allows:

• Implement different routing instances on the same device

• Convert Layer 3 router into Layer 2 switch

• Provide Layer 1 switch functionality with routing

• Provide routing capabilities to switch-router

QoS in MPLS network requires:

• Use routing protocols like OSPF/IS-IS

• Replace LDP with CSPF

• Use QoS-supporting protocol like RSVP

• Implement DiffServ-supporting mechanisms

Regarding MPLS:

• DS-MPLS-TE merges TE with QoS in MPLS

• MPLS-TE splits bandwidth across priorities

• TE defines service classes in virtual circuit

• MPLS-TE avoids congestion by FEC redistribution

Router Distinguisher functionality:

• Offloads router processing

• Defines backup routes

• Solves overlapping IP addresses

• Merges QoS techniques

About Router Distinguisher, which is incorrect:

• Formed by 32 bits

• Used as MPLS VPN identifier

• Unique prefix for MPLS VPN

• Added to customer IPs

Incorrect statement about IP Precedence/DSCP:

• Both exist in IPv4/IPv6 headers

• IP Precedence defines 8 priorities

• DSCP defines 6 AF classes with 4 drop probabilities

• DiffServ uses either for service levels

Outdated VPN technologies:

• PPTP, L2TP, MPLS VPNs

• IPSec, SSL/TLS, PPTP

• PPTP, L2TP, SSL

• MPLS, IPSec, TLS

IPSec VPN modes:

• Transport protects entire IP packet

• Tunnel keeps original IP header

• Transport encrypts only payload

• Both encrypt entire packet

IPSec and NAT:

• IPSec compatible with NAT

• NAT encrypts all but physical layer

• NAT traversal works on UDP/TCP equally

• NAT traversal adds UDP header