Network Fundamentals

A technician finds that one of the four pairs in a Category 5e cable is broken. The link worked at 100 Mb/s but now must run at 1 Gb/s with 1000BASE-T. Why will the gigabit link have a problem?

A technician plans a 1000BASE-T run of Category 6 cable from a switch to a desk. What is the maximum length of this copper segment?

Two older switches must be connected with a copper cable, and neither switch supports Auto-MDIX. Which cable type is needed?

A factory floor has large motors that create strong electromagnetic interference. Which medium avoids this interference on a 90 meter link?

An interface counter shows a rising number of giants. What does this counter record?

A switch port is hard-coded to speed 100 and duplex full, which disables autonegotiation on it. The attached PC is left on autonegotiation. What does the PC most likely end up with?

A router sends log messages to a syslog server and synchronizes its clock with an NTP server. Which pair of default UDP ports does this traffic use?

An administrator must permit secure remote command-line access to routers through a firewall. Which transport protocol and port does this traffic use by default?

A switch has empty SFP slots on its uplink side. What does an SFP slot let the engineer do?

An engineer compares protocol overhead. What are the minimum header sizes of TCP and of UDP?

A web download over TCP loses one segment in transit. How does TCP recover?

A file server sends data over TCP to a slow backup appliance. The appliance advertises a smaller window size in its acknowledgments. What is the effect on the server?

A serial WAN interface on R4 shows the status "Serial0/1/0 is up, line protocol is down". What does this tell the engineer?

In a three-tier campus design, which job belongs to the core layer?

A retailer has 40 stores. Each store has one WAN connection to the head office data center, and stores reach each other only through the head office. Which WAN topology is this?

A network engineer must choose between an intrusion detection system and an intrusion prevention system for the data center edge. The requirement is that malicious packets are dropped before they reach the servers. Which statement explains why an IPS meets this requirement?

In a small company network, which device is best described as a server rather than an endpoint?

A dentist runs a three-person office from a small suite. A single device from the internet provider routes to the internet, gives out addresses, has four Ethernet ports and broadcasts the office Wi-Fi. Which topology description fits this network?

A network team needs at least 12 equal subnets from 192.168.100.0/24 and wants as many hosts per subnet as possible. How many usable hosts will each subnet have?

A branch has been given 10.20.0.0/22 and splits it into /26 subnets. How many /26 subnets can it create?

How many usable host addresses does a /23 subnet provide?

A host is set to 172.20.77.99 with mask 255.255.224.0. Which range of addresses does its subnet cover?

A large enterprise wants a single private block that can hold the most /24 subnets. Which RFC 1918 block should it choose?

A company uses 10.0.0.0/8 internally. Why must its edge router translate these addresses before traffic reaches internet hosts?

Which RFC 1918 private block uses a /12 prefix?

Refer to the output from BR-EDGE.BR-EDGE# show ip interface GigabitEthernet0/0/2 GigabitEthernet0/0/2 is up, line protocol is up Internet address is 172.16.9.14/29 Broadcast address is 255.255.255.255What is the directed broadcast address of the subnet connected to GigabitEthernet0/0/2?

Two routers share a point-to-point Ethernet link, and the team wants to use both addresses of a two-address subnet without losing any to network or broadcast use, as RFC 3021 allows. Which prefix length does this use?

An OSPF area border needs a summary for 172.20.16.0/24 through 172.20.23.0/24, eight networks in all. Which summary covers exactly these networks?

A site uses only 10.3.64.0/24, 10.3.66.0/24 and 10.3.70.0/24. What is the smallest single summary route that covers all three?

R1 uses 10.0.12.1/30 on its link to R2. An engineer tries to give R2 the address 10.0.12.3/30 on the same link, and IOS rejects it. Which address should R2 use?

A router interface with MAC address 02AB.CD12.3456 uses EUI-64 with the prefix 2001:db8:acad:20::/64. Which address does it build?

Refer to the output from R3.R3# show ipv6 interface brief GigabitEthernet0/0/0 [up/up] FE80::2A3:D1FF:FE45:6B01 2001:DB8:ACAD:10::1 GigabitEthernet0/0/1 [up/up] FE80::2A3:D1FF:FE45:6B02 2001:DB8:ACAD:20:2A3:D1FF:FE45:6B02The GigabitEthernet0/0/1 addresses were built with modified EUI-64. What is that interface's MAC address?

A host sends a Router Solicitation to find routers on its link. Which destination address does it use?

Global unicast addresses are currently assigned from which IPv6 range?

An engineer wants a router interface facing the provider to build its own IPv6 global address from the prefix in the provider's router advertisements. Which interface command does this?

Which address is identical to 2001:db8:0:5:0:0:0:1a?

IPv6 has no broadcast addresses. What does a host use when it must reach every IPv6 node on the local link?

A host has the address 2001:db8:1234:5678::1. What is its /56 prefix?

Which Linux command displays the host's default gateway?

Refer to the output from a Linux host.$ ip addr show ens3 2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 52:54:00:7b:10:e4 brd ff:ff:ff:ff:ff:ff inet 192.168.40.18/24 brd 192.168.40.255 scope global ens3 inet6 fe80::5054:ff:fe7b:10e4/64 scope linkHow was the interface ID of the IPv6 address built?

A technician wants to test the IPv6 stack on a workstation without sending anything onto the network. Which address is the IPv6 equivalent of 127.0.0.1?

Refer to the output from a Mac.$ ifconfig en0 en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 ether 8c:85:90:4e:21:7a inet6 fe80::1c4f:2a9b:7e10:d3c5%en0 prefixlen 64 secured scopeid 0xb inet 172.16.30.25 netmask 0xfffffe00 broadcast 172.16.31.255 status: activeWhat is the IPv4 prefix length of en0?

Which solicited-node multicast address does a host join for its unicast address 2001:db8::20c:29ff:fe3a:4b5c?

A Windows PC was moved to a new VLAN and still holds its old DHCP address. Which command asks the DHCP server for a new lease?

A Windows PC's ipconfig output shows "Link-local IPv6 Address . . . : fe80::9c1d:44b2:e01a:5f3%12". What does %12 mean?

A host in VLAN 30 sends an ARP request to the broadcast address FFFF.FFFF.FFFF. How does the switch handle the frame?

A 24-port switch has all ports in VLAN 1, each running full duplex to one host. How many broadcast domains does this switch create?

A switch has 0050.7966.6840 learned on Gi1/0/18 in VLAN 40. A frame in VLAN 40 for that MAC arrives on Gi1/0/2. What does the switch do?

A printer was unplugged an hour ago, and its MAC address no longer appears in the switch's dynamic MAC address table. Why was the entry removed?

A frame arrives on switch port Gi1/0/5 with source MAC 0050.7966.6810 and destination MAC 0050.7966.6820. Which MAC address does the switch learn, and on which port?

A switch receives a whole frame into memory, checks its FCS and discards it if the check fails. Which switching method is this?

A server administrator creates a virtual machine on a hypervisor. What does each virtual machine contain?

On router PE1, interface GigabitEthernet0/0/1 had the address 10.1.1.1/24. An engineer then entered vrf forwarding CUST-A on that interface, and now the customer cannot ping 10.1.1.1. What is the most likely reason?

A service provider router connects two customers that both use 10.1.1.0/24 internally. Which feature lets the router keep a separate routing table for each customer so that the overlapping networks do not conflict?

On a virtualization host, eight virtual machines must talk to each other and to the physical network through the host's two network adapters. Which component makes this possible?

A conference center moves its Wi-Fi from 2.4 GHz to 5 GHz. Which statement compares the 5 GHz band with 2.4 GHz correctly?

A wireless survey tool lists the SSID Staff-Net several times, each with a different 48-bit hardware address. What are those addresses?

Two laptops connect directly to each other over Wi-Fi with no access point involved. Which 802.11 service set is this?

Users in a break room lose Wi-Fi throughput every time the microwave oven runs. Which change is most likely to help?