1. 192.168.10.0/26 is subnetted. What is the usable host range of the second subnet? 192.168.10.64 to 192.168.10.127 192.168.10.65 to 192.168.10.126 192.168.10.63 to 192.168.10.126 192.168.10.65 to 192.168.10.127
Check answer 2. A voice application is chosen to run over UDP rather than TCP. Which property of UDP is the reason? It guarantees delivery, which voice traffic requires It reorders segments on arrival, which removes jitter It is connectionless and does not retransmit, so a late packet is never resent It uses a three-way handshake that is faster than TCP's
Check answer 3. A host at 10.1.1.10/24 sends a packet to 203.0.113.5. Whose MAC address does it need, and how does it get it? The destination host's, learned by an ARP request broadcast on the local segment Its default gateway's, learned by an ARP request for the gateway's IP address The destination host's, learned from the router by a proxy DNS lookup Its default gateway's, which is supplied inside the IP header of the outbound packet
Check answer 4. An interface shows an IPv6 address beginning fe80::. What kind of address is it? A unique local address, routable within the organisation but not on the internet A global unicast address assigned by the provider A link-local address, valid only on that link and never routed off it A multicast address used for neighbour discovery
Check answer 5. What does creating a second VLAN on a switch actually change? It creates a second broadcast domain, so a broadcast in one VLAN is never flooded into the other It creates a second collision domain per port, doubling available bandwidth It allows two subnets to share one broadcast domain safely It enables routing between the two groups of ports without any Layer 3 device
Check answer 6. Hosts in VLAN 30 on one access switch get no DHCP address. VLAN 10 hosts on that switch are fine, and VLAN 30 hosts on a different switch are fine. Where do you look first? The DHCP server's pool for VLAN 30, since the symptom is a DHCP failure The uplink trunk on the failing switch, checking whether VLAN 30 is in its allowed list Spanning tree, since a blocked port would explain a total loss of service The DHCP relay configuration on the server, since one switch is affected
Check answer 7. How does spanning tree choose the root bridge? The switch with the highest bridge ID, comparing priority first and then MAC address The switch with the most active ports, breaking ties by uptime The switch with the lowest bridge ID, comparing priority first and then MAC address The switch configured with the lowest port cost on its uplink
Check answer 8. In a split-MAC deployment with lightweight access points and a wireless LAN controller, how do the access points reach the controller? Through CAPWAP tunnels, which carry both control and data traffic between AP and controller Directly over untagged Ethernet, since lightweight APs bridge locally by default Through an IPsec site-to-site VPN built by each AP at boot They do not — each lightweight AP is configured independently, like an autonomous AP
Check answer 9. A routing table holds 10.1.0.0/16 via R2, 10.1.1.0/24 via R3, and 0.0.0.0/0 via R4. Which is used for a packet to 10.1.1.50? 0.0.0.0/0 via R4, because a default route is always evaluated first 10.1.0.0/16 via R2, because it was learned by a protocol with a lower administrative distance 10.1.1.0/24 via R3, because it is the longest matching prefix The router load-balances across all three, since all three match
Check answer 10. A router learns 192.168.5.0/24 from OSPF (administrative distance 110) and also has a static route for exactly 192.168.5.0/24. Which is installed in the routing table, and why? The OSPF route, because a dynamic protocol has current topology information The static route, because its administrative distance of 1 is lower and therefore more trusted Both, and the router load-balances between them Neither — the conflict causes the router to discard both entries
Check answer 11. In show ip route output, an entry marked L with a /32 mask appears alongside a connected network. What is it? A host route learned from a neighbour advertising a single address A leftover route awaiting removal after an interface went down A loopback address the router generated automatically for management The local route for the router's own address on that interface
Check answer 12. Two directly connected routers will not form an OSPF adjacency. Which pair of values must match between them? Router IDs and process IDs Area ID and hello and dead timers Hostnames and interface descriptions Administrative distance and interface bandwidth
Check answer 13. A host cannot reach a remote network. Applying dependency order, which do you confirm first and why? The OSPF neighbour table, because a missing route is the most likely cause The access lists on the path, because policy is the most common cause of a black hole The interface state and VLAN assignment, because everything above them assumes they are already correct The DNS configuration on the host, because name resolution precedes routing
Check answer 14. Where should a standard IPv4 access list be placed, and why does an extended one differ? Standard close to the destination, because it matches only the source address; extended close to the source, because it can match both addresses and ports Standard close to the source, because it filters earliest; extended close to the destination, because it needs more context Both close to the source, because filtering early always saves bandwidth Both close to the destination, because only the destination router knows the full path
Check answer 15. Port security is configured on an access port with default settings and an unexpected MAC address appears. What happens? The frame is dropped and a syslog message is generated, but the port stays up The port is placed in err-disabled state, because the default violation mode is shutdown The MAC address is added as a sticky entry and traffic continues The port begins rate-limiting traffic from the unknown address
Check answer 16. Which set of steps is required before SSH can be used to manage a Cisco device? Enable a Telnet password, then set transport input all on the vty lines Set an enable secret and enable HTTP, which SSH depends on for key exchange Configure a hostname and a domain name, generate crypto keys, create a local user, and set transport input ssh on the vty lines Generate crypto keys only — everything else is enabled by default
Check answer 17. What is the correct order of the four DHCP messages when a client gets an address? Discover, Offer, Request, Acknowledge Request, Discover, Offer, Acknowledge Offer, Discover, Acknowledge, Request Discover, Request, Offer, Acknowledge
Check answer 18. Fifty internal hosts share a single public address for internet access. What lets the router return each reply to the right host? A static one-to-one mapping created for each host in advance The source port number, which PAT rewrites and tracks per translation The MAC address of the originating host, carried end to end A separate public address allocated to each host from a NAT pool
Check answer 19. Which pair of statements about Ansible is correct? Agent-based and pull; playbooks are written in HCL Agentless and push; playbooks are written in YAML Agentless and pull; playbooks are written in Ruby Agent-based and push; playbooks are written in YAML
Check answer 20. What does terraform plan compare, and why does that matter operationally? Two versions of the configuration file, so you can review a code change before merging it The declaration, the state file, and reality, producing the exact changes needed and revealing drift The current run against the previous run's log, so repeated runs can be skipped The inventory against the devices, so unreachable hosts are reported before the run
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