Network Troubleshooting and Tools Flashcards
A home user performs a speed test using SpeedTest.net and receives the following report:
The user’s PC is receiving data at 99.79 Mbps and sending data to the server at 116.61 Mbps.
You are a network administrator troubleshooting an issue with a newly-installed web server. The web server is available to internal network users, but users outside the internal network (Internet users) cannot reach the server. You run an IPCONFIG and receive the configuration below:
NAT has not been configured on the border firewall.
Your company has two office buildings which are connected via a copper network cable that is buried underground. There is some construction being performed near the buildings. Now, the second building discovers they have suffered a network outage that doesn’t appear to be temporary. What is the MOST likely cause of the outage?
An open circuit has been created
A technician has installed an 802.11n network, and most users can see speeds of up to 300Mbps. A few of the users have an 802.11n network card but cannot get speeds higher than 108Mbps. What should the technician do to fix the issue?
Upgrade the WLAN card driver
A technician installs a new WAP, and users in the area begin to report poor performance. The technician uses ping, and only 3 of the 5 packets respond. When the technician tests the connection from a wired connection, it responds with 5 of 5 packets. What tool should the network technician use next?
Spectrum analyzer tool
A network technician connects three temporary office trailers with a point-to-multipoint microwave radio solution in a wooded area. The microwave radios are up, and the network technician can ping devices in all office trailers. However, connectivity is sporadic. What is the cause of this issue?
Interference
You are troubleshooting the network connectivity between a remote server and your workstation. Which of the following tools should you use to determine the connection path between your workstation and the remote server?
Pathping
What tool would a network technician use to troubleshoot a span of single-mode fiber cable?
OTDR
An administrator arrives at work and is told that network users are unable to access the file server. The administrator logs into the server and sees the updates were automatically installed last night, and the network connection shows “limited” with no availability. What rollback action should the technician perform?
Server’s NIC drivers
Tim is a network administrator who is setting up three additional switches in his test lab. While configuring the switches, he verifies the connectivity but finds that when he pings one of the switches using its IP address, he receives “Destination Unreachable.” What kind of issue is this?
Misconfigure split-horizon
A network technician has just run a new point-to-point fiber link between two local routers. After the fiber has been plugged in on both ends, the interface will not come up. The network technician has double-checked the interface configuration on both routers, both SFPs have been hard looped to confirm they are functioning, connectors on both ends of the links have been cleaned, and there is sufficient power. What is the cause of the problem?
Wavelength mismatch
Your company has just gotten a new OC-12 installed to support your server room. The telecommunications provider has installed the connection from their main offices to your demarcation point. When the installers test the provider’s connection to your demarcation point, everything works properly. You connect the OC-12 to your network, but you are noticing many dropped packets and errors. You suspect this may be a layer 1 issue. Which of the following should you attempt FIRST to identify the source of the issue?
Use an OTDR to validate the cable’s integrity
You are working as a service desk analyst. This morning, you have received multiple calls from users reporting that they cannot access websites from their work computers. You decide to troubleshoot the issue by opening up your command prompt on your Windows machine and running a program to determine where the network connectivity outage occurs. Which tool should you use to determine if the issue is on the intranet portion of your corporate network or if it is occurring due to a problem with your ISP?
Tracert
A user is unable to connect to a server in another building and discovers the following while troubleshooting the issue:
1) Client PC 1 has an IP address if 172.16.10.25/25
2) PC 1 can successfully ping its gateway of 172.16.10.1/25, which is an interface of router A
3) Server A is named “BLDGRILFESVR01’ and has an IP address of 172.16.10.145/25
4) PC 2 with an IP address of 172.16.10.200/25 can successfully ping server A
However, when PC 1 pings Server A, it gets an error of destination host unreachable. Which of the following might be the issue?
Link from SERVER A to PC 1 are on different subnets
An organization requires a second technician to verify changes before applying them to network devices. When checking a network device’s configuration, a technician determines that a coworker has improperly configured the AS number on the device. Which of the following might be the result of this?
BGP routing issues
While troubleshooting, a technician notices that some clients using FTP still work and that pings to the local routers and servers are working. The technician tries to ping all known nodes on the network, and they reply positively, except for one of the servers. The technician notices that ping works only when the hostname is used but not when FQDN is used. What server is MOST likely offline?
DNS server
(This is a simulated Performance-Based Question.)
You are testing a cable you found in your network closet. You connect a cable tester to both sides of the cable to verify the pinout of the Ethernet cable. After testing each pin, your cable tester gives you the following output:
Patch cable
What can be issued from the command line to find the layer 3 hops to a remote destination?
Traceroute
A network technician is troubleshooting connectivity problems between switches but suspects the ports are not properly labeled. What option will help to identify the switches connected to each port quickly?
Enable a discovery protocol on the network devices
Multiple students within a networking lab are required to simultaneously access a single switch remotely. The administrator checks and confirms that the switch can be accessed using the console, but currently, only one student can log in at a time. What should be done to fix this issue?
Increase the number of virtual terminals available
A user has installed a new wireless printer on the network. The user cannot get it connected to the Internet but can print locally. All other office users can reach the Internet but cannot connect to the new wireless printer. All users are wireless in this part of the office. What MOST likely has occurred?
They installed the printer in ad-hoc mode
An end-user receives a new computer and now is unable to connect to a database using ODBC. Other users can connect successfully, and the network technician can successfully ping the database server but still is unable to connect. What might have caused this issue?
Software firewall is blocking ports
You have just upgraded a small office LAN switch. When you finish, a user states they can no longer access the network. You check the user’s workstation but do not see any LED lights lit on their NIC. What should you check next?
Verify the network cable is attached to the new switch
Several users at an adjacent office building report connectivity issues after a new building was built in-between the two offices. The network technician has determined the adjacent office building is connected to the main office building via an 802.11ac bridge. The network technician logs into the AP and confirms the SSID, encryption, and channels are all correct. Which of the following is MOST likely the cause of this issue?
Interference
Lynne is a home user who would like to share music throughout the computers in her house using an external USB hard drive connected to a router that she purchased over a year ago. The manufacturer states that the router can recognize drives up to 4TB in size, but she cannot get her 3TB hard drive to show up on the network. What should Lynne do to fix this problem?
Flash the latest firmware for her router
A network technician needs to monitor the network to find a user who is browsing websites against the company policy. What should the technician use to view the website and find the user browsing it?
Packet sniffer
You are working as a wireless networking technician and have been sent to a user’s home to install a brand new 802.11 AC WAP to replace their old WAP. To ensure all of the current devices on the network will automatically connect to the new network, you set the SSID, encryption type, and password to the same ones as the old WAP. You turn the new WAP on and notice most of the devices connect automatically, but one older wireless printer won’t connect. You notice that the printer is about 7 years old, but the user says it has always worked great over the old wireless network. What is the MOST likely reason that the printer will not connect to the new WAP?
There is a mismatch in frequencies
A technician is tasked with troubleshooting a network’s slowness. While troubleshooting, the technician is unable to ping any external websites. Users report they can access the sites using the web browsers. What is the MOST likely cause?
ICMP traffic being blocked by the firewall
A network technician was tasked to install a network printer and share it with a group of five human resource employees. The technician plugged the device into a LAN jack but was unable to obtain an IP address automatically. What is the cause of the problem?
DHCP scope is exhausted
A network technician determines that two dynamically-assigned workstations have duplicate IP addresses. What command should the technician use to correct this issue?
ipconfig / release; ipconfig /renew
A network administrator is troubleshooting an issue with unstable wireless connections in a residence hall. Users on the first and second floors report that the hall’s SSID is not visible in the evenings. The network administrator has verified that the wireless system is operating normally. What is the cause of the issue being reported by the users?
Internet router maintenance is scheduled
A technician installs three new switches to a company’s infrastructure. The network technician notices that all the switch port lights at the front of each switch flash rapidly when powered on and connected. Additionally, there are rapidly flashing amber lights on the switches when they started up the next day. What is happening to the switches?
The switches are running through their spanning tree process
(This is a simulated Performance-Based Question.)
You have been tasked with testing a CAT 5e network cable. After conducting the test using the tool provided by your manager, you see the following test results:
Cable certifier
The results of the cable certifier are shown below: Cable test results
1, 2 —- Open — 3 ft
3, 6 —– Short – 3 ft
4, 5 — Open —- 3 ft
7, 8 — Open – 3 ft
Using the results provided, was the cable properly crimped or not?
Cable was not properly crimped
A technician suspects that the email system is slow due to an excessive amount of Spam being received. Which of the following should the technician do FIRST according to the troubleshooting methodology?
Gather information
You have just installed a new switch in your company’s network closet. The switch connects to your router using an SFP port on both the router and switch. Unfortunately, you only had a long cable available to make the connection, so after running the cable from the rack containing the switch to the other rack containing the router, you decide to coil up the excessive cable and use a zip tie to hold the coil to the side of the rack. You head back to your office, log into the switch over SSH, and check the log file. You notice that several messages indicate that the signal strength on the transmit portion of the SFP is registering as too weak. What is the BEST explanation for the cause of this error?
The bend radius of the cable has been exceeded
A company suffers an outage due to a bad module in a core switch. What is the NEXT step to conduct troubleshooting?
Establish a plan of action to solve the problem
Single-mode fiber is not providing network connectivity to a remote site. Which of the following could be used to identify the location of the break in the fiber?
OTDR
A network technician discovers an issue with the spanning tree on the core switch. Which step should the network technician perform NEXT when troubleshooting to resolve the issue?
Establish a theory of probable cause
The RAID controller on a server failed and was replaced with a different brand. What will be needed after the server has been rebuilt and joined to the domain?
Recent backups
The administrator’s network has OSPF for the internal routing protocol. One port going out to the internet is congested. The data is going out to the internet but queues up before sending. What would resolve this issue?
Output: Fast Ethernet 0 is up, line protocol is up Int ip address is 10.20.130.5/25 MTU 1500 bytes, BW 10000 kbit, DLY 100 usec Reliability 255/255, Tx load 1/255, Rx load 1/255 Encapsulation ospf, loopback not set Keep alive 10 Half duplex, 100Mb/s, 100 Base Tx/Fx Received 1052993 broadcasts 0 input errors 983881 packets output, 768588 bytes 0 output errors, 0 collisions, 0 resets
change duplex to full
Your company is using a T1 connection for its connectivity to the internet. When you arrived at work this morning, you found that your internet connection was not working properly. You began troubleshooting and verified that the network’s router is properly configured, the cable is connected properly between the router and the T1’s CSU/DSU, but the T1 remains down. You call your ISP, and they have requested that you test the interface on the CSU/DSU to ensure it hasn’t failed. Which tool should you utilize to perform this test?
Loopback adapter
You are troubleshooting a wireless network. A user has complained that their iPad cannot connect to the wireless network from their desk in the building’s corner. The user has no issues connecting to the wireless network with the tablet when located in the break room area at the center of the building. You measured the distance from their office to the 802.11 AC wireless access point, and it is about 170 feet. What is MOST likely the cause of the tablet not connecting to the WAP?
Distance
The network administrator is troubleshooting a switch port for a file server with dual NICs. The file server needs to be configured for redundancy, and the dual NICs need to be combined for maximum throughput. What feature on the switch should the network administrator ensure is enabled for best results?
LACP
A company has added many new users to the network that is causing an increase in network traffic by 200%. The engineers’ original projection was that the new users would only add 20-30% more network traffic, not 200%. The network administrator suspects that a compromise of the network may have occurred. What should the network administrator have done previously to prevent this network breach?
Provide end user awareness and training for employees
Sally, in the web development group, has asked for your assistance in troubleshooting her latest website. When she attempts to connect to the web server as a user, her web browser issues a standard HTTP request but continually receives a timeout response in return. You decided to capture the entire TCP handshake between her workstation and the webserver to troubleshoot the issue best. Which of the following tools would BEST allow you to capture and then analyze the TCP handshake?
Protocol analyzer
A user reports slow computer performance. A technician troubleshooting the issue uses a performance monitoring tool and receives the following results:
Avg % Processor Time =10%
Avg Pages/Second = 0
Avg Disk Queue Length = 3
Based on the results, what might be causing a performance bottleneck?
Hard drive
A technician is troubleshooting an area that is having difficulty connecting to a WAP. After identifying the symptoms, what should the technician do NEXT?
Establish the probable cause
An administrator has configured a new 100 Mbps WAN circuit, but speed testing shows poor performance when downloading larger files. The download initially reaches close to 100 Mbps but begins to drop and show spikes in the download speeds over time. The administrator checks the router interface and sees the following:
NETRTR01# show interface eth 1/1 GigabitEthernet 1/1 is up, line is up
Hardware is GigabitEthernet, address is 000F.33CC.F13AConfigured speed auto, actual 1Gbit, configured duplex fdx, actual fdx
Member of L2 VLAN 1, port is untagged, port state is forwarding
What is the issue?
Remove default 802.1q tag and set to sever VLAN
You are troubleshooting your company’s T-1 connection to your ISP. The ISP has asked you to place a loopback on the device which connects your T-1 line to their central office. Which of the following devices should you connect the loopback plug on?
Channel service unit
An administrator’s router with multiple interfaces uses OSPF. When looking at the router’s status, it is discovered that one interface is not passing traffic. Given the information below, what would resolve this issue?
Output:
Fast Ethernet 0 is up, line protocol is down
Int ip address is 10.20.130.5/25
MTU 1500 bytes, BW 10000 kbit, DLY 100 usec
Reliability 255/255, Tx load 1/255, Rx load 1/255
Encapsulation ospf, loopback not set
Keep alive 10
Full duplex, 100Mb/s, 100 Base Tx/Fx
Received 1052993 broadcasts
0 input errors 0 packets output, 0 bytes
0 output errors, 0 collisions, 0 resets
Enable the connecting port
A wireless networking technician has completed a wireless network survey and documented the detected signal strengths in various locations. What is this document called?
Heat map
A network administrator is configuring a VLAN across multiple switches. The administrator wants to configure the VLAN once and have that configuration propagate to all of the network switches. Which of the following should the administrator do?
Configure the switches to utilize VTP
You are working as a network technician and need to create several Cat 5e network cables to run between different computers and the network jacks on the wall. The connections between the switch, the patch panel, and the wall jacks have already been installed and tested. Which of the following tools would NOT be necessary to complete this task?
Punchdown tool
You are assisting a member of your organization’s security team during an incident response. The team member asks you to determine if any strange TCP connections are occurring on a given workstation. You open the command prompt on the workstation. Which of the following tools would provide you with information on any TCP connections currently on the workstation?
netstat
(This is a simulated Performance-Based Question.) A customer’s email service is not sending emails anymore. What is the correct order that you should follow to perform the troubleshooting steps?
Determine if any recent changes have been made to the server; Establish a theory of probable cause; Test the theory to determine the cause; Establish a plan of action to resolve the problem; Implement the solution; Verify full system functionality; implement preventative measure; document findings, actions, and outcomes
A network technician has configured a point-to-point interface on a router. Once the fiber optic cables have been run, though, the interface will not come up. The technician has cleaned the fiber connectors and used an optical power meter to confirm that light passes in both directions without excessive loss. What is the MOST likely cause of this issue?
Wavelength mismatch
A network technician receives the following alert from a network device:
“High utilization threshold exceeded on gi1/0/24: current value 8463257.54”
What is being monitored to trigger the alarm?
Interface link status
A home user reports that a speed test website shows the following information:
Download speed: 33.3 Mbps
Upload speed: 10.2 Mbps
Which of the following is the best interpretation of the results?
The home PC is receiving data at 33.3 Mbps and sending data at 10.2 Mbps
A network technician needs to identify active services that should be disabled on the network. What tool would BEST accomplish this?
Port scanner
A technician just completed a new external website and setup access rules in the firewall. After some testing, only users outside the internal network can reach the site. The website responds to a ping from the internal network and resolves the proper public address. What can the technician do to fix this issue while causing internal users to route to the website using an internal IP address?
Implement a split-horizon DNS
What should be considered when troubleshooting the coverage and signal strength of an 802.11n WLAN?
Building materials in the area
A company is experiencing accessibility issues reaching services on a cloud-based system. What monitoring tools should be used to locate possible outages?
Network analyzer
(This is a simulated Performance-Based Question. On the real certification exam, you will be asked to click on the appropriate device to see and modify its configuration.)
Wireless network users recently began experiencing speed and performance issues on your network after Access Point 2 (AP2) was replaced due to a recent hardware failure. The original wireless network was installed according to a wireless consultant’s specifications and has always worked properly without any past issues.
You have been asked to evaluate the situation and resolve any issues you find to improve the network’s performance and connectivity. The client has instructed you to adjust the least amount of settings/configurations possible while attempting to fix the issue. Before arriving on-site, you receive the below office’s floor plan with an elementary network diagram drawn on top.
Based on the information provided to you so far, which network device would you log into first to begin your troubleshooting efforts?
AP2
You just arrived at school today, pulled your laptop out of your backpack, and tried to connect your laptop to the Wi-Fi network. It worked fine yesterday, but today it won’t connect automatically or display any available networks. You haven’t done anything to the laptop since you left class yesterday. You ask your classmates if they can connect to the Wi-Fi, and every one of them is connected without any issues. What should you check FIRST in your attempt to connect your laptop to the Wi-Fi?
Wireless switch on your laptop
A technician is attempting to resolve an issue with users on the network not accessing websites. The technician pings the default gateway and DNS servers successfully. Pinging a website by URL is unsuccessful but using a known IP address is successful. What would resolve the issue?
Enable port 53 on the firewall
A network technician responds to a customer reporting that a workstation continually loses the connection to the network. The user explains that it occurs randomly, and it happens several times throughout the day. Which step of the troubleshooting method should the technician perform first?
Gather information
A network administrator recently set up a network computer lab and discovered some connectivity issues. The administrator can ping the fiber uplink interface, but none of the new PCs plugged into the switch respond to ICMP requests. What should the technician do next?
Check if there are link lights on the ports
A switch technician is tasked to centrally manage the switches and segment the switches by broadcast domains. The corporate network is currently using VLAN 1 for all of its devices and uses a single private IP address range with a 24-bit mask. The supervisor wants VLAN 100 to be the management subnet and all switches to share the VLAN information. What option would be best to use?
Use VLSM on the IP address range with VTP and 802.1q on the inter-switch connections with native VLAN 100
You are currently troubleshooting a network connection error. When you ping the default gateway, you receive no reply. You checked the default gateway, and it is functioning properly, but the gateway cannot connect to any of the workstations on the network. Which of the following layers could be causing this issue?
Physical
Your company has been asked by a local charity that supports underprivileged youth if they would help to build an internet café for their students. Because the charity doesn’t have any funding for this project, your company has decided to donate their old workstations and networking equipment to create the network. All of the workstations, routers, and switches have been tested before installation. The company has decided to reuse some old network cables to connect the computers to the switches to save money. When you arrive at the new internet cafe, you are told that everything is working except unlucky computer #13 can’t connect to the network. You attempt to plug the network cable into another computer, but then that computer cannot connect to the network. Confused, you try connecting the cable directly between two computers, and now they can communicate directly with each other. What is wrong with this cable?
The cable is a crossover cable but should be a straight-through cable
You are trying to connect to another server on the network but are unable to do so. You have determined that the other server is located on the 10.0.0.1/24 network, but your workstation is located on the 192.168.1.1/24 network. Which of the following tools should you use to begin troubleshooting the connection between your workstation and the server?
Traceroute
A technician is troubleshooting a PC that is having intermittent connectivity issues. The technician notices that the STP cable pairs are not completely twisted near the connector. Which of the following issues may be experienced due to this?
Cross-talk
A wireless technician wants to configure a wireless network to identify itself to visitors by including the word “Guest” in the name. This wireless network needs to provide coverage to the entire building and requires 3 wireless access points to accomplish this coverage level. What would allow users to identify the wireless network by its displayed name as a single network?
ESSID broadcast
A technician has attempted to optimize the network, but some segments are still reporting poor performance. What issue should the technician look at?
Packet bottlenecks
You are working as a network technician and have been asked to troubleshoot an issue with a workstation. You have just established a theory of probable cause. Which of the following steps should you perform NEXT?
Test the theory to determine cause
A network technician must replace a network interface card on a server. The server currently uses a multimode fiber to uplink a fiber switch. Which of the following types of NICs should the technician install on the server?
10GBase-SR
An administrator has configured a new 100Mbps WAN circuit, but speed testing shows poor performance when downloading large files. The download initially reaches close to 100Mbps but begins to drop and show spikes in the download speeds over time. The administrator checks the router interface and sees the following:
Router01# show interface eth1/1
GigabitEthernet1/1 is up, line is up
Hardware is GigabitEthernet, address is FF12.CDEA.1426
Configured speed auto, actual 1Gbit, configured duplex fdx, actual fdx
Member of L2 VLAN 1, port is untagged, port state is forwarding
Which of the following is the best solution to resolve this issue?
Remove default 802.1q tag and set to server VLAN
After some recent changes to the network, several users are complaining that they cannot access the servers. You have been provided with the Internet Protocol Version 4 (IPv4) Properties for PC1, PC2, PC3, and PC4.
Which of the following actions should you perform to fix the issue and ensure the computers can communicate with the servers again?
Change PC3’s subnet mask to 255.255.255.0
A client reports that half of the marketing department is unable to access network resources. The technician determines that the switch has failed and needs replacement. What would be the MOST helpful in regaining connectivity?
Configuration backup
A technician has been troubleshooting a network problem, has determined the most likely cause of the issue, and implemented a solution. What is the NEXT step to be taken?
Verify system functionality
The service desk has received many calls this morning complaining about how slow the network is responding when trying to connect to the internet. You are currently at one of the user’s workstations and conducted a ping to Google.com, but the results showed that the response time was too slow, and there was too much latency in the route between the workstation and Google.com. You then attempted to ping some of the network printers and other local servers on the network. The results showed acceptable response times. What should you try to do NEXT?
Check the change control system to determine if any networking equipment was recently replaced
It has been determined by network operations that there is a severe bottleneck on its mesh topology network. The field technician has chosen to use log management and found that one router makes routing decisions slower than the others on the network. What is this an example of?
Network device CPU issues
A network administrator is noticing slow response times from the server to hosts on the network. After adding several new hosts, the administrator realizes that CSMA/CD results in network slowness due to congestion at the server NIC. What should the network administrator do?
Add additional network cards to the server
You have just moved into a new condo in a large building. Your wireless network is acting strangely, so you are worried that it may be due to interference from the numerous other wireless networks in the building since each apartment has its own wireless access point. You want to determine what wireless signals are within the walls of your apartment and their relative strength. What technique should you utilize to determine whether the nearby wireless networks are causing interference with your own Wi-Fi network?
Conduct a site survey within your apartment
Today, your company’s network started to experience network connectivity issues for various workstations around the company. As you begin troubleshooting, you identify that all the workstations receive their connectivity from a single switch on the 3rd floor of the office building. You start searching the 3rd floor for the cause of this issue and find a small wired router plugged into a network jack in the sales manager’s office. From this small wired router, he has connected his workstation and a small Smart TV to watch Netflix while working. You question the sales manager about when he brought in the new router. He states that he just hooked it up this morning. What type of issue did the sales manager accidentally introduced into the network by installing the router?
Rogue DHCP server
A desktop computer is connected to the network and receives an APIPA address but cannot reach the VLAN gateway of 10.10.100.254. Other PCs in the VLAN subnet can reach the Internet. What is the MOST likely source of the problem?
802.1q is configured on the switch port
A technician is troubleshooting a desktop connectivity issue. The technician believes a static ARP may be causing the problem. What should the technician do NEXT according to the network troubleshooting methodology?
Remove the ARP entry on the user’s desktop
Your company just moved into a beautiful new building. The building has been built with large glass windows covering most of the walls and ceiling to provide natural light to be visible throughout the offices. You have noticed that your cell phone gets poor cellular connectivity when inside the building. What is the MOST likely cause of the poor cellular service within the building?
Reflection
Users are reporting extreme slowness across the network every Friday. What should the network technician review first to narrow down the root cause of the problem?
Utilization
Michael is a system administrator who is troubleshooting an issue remotely accessing a new server on the local area network. He is using an LMHOST file, which contains the hostname and IP address of the new server. He cannot remotely access the server on the same LAN as another server that he can successfully remote to. What output from the command line would BEST resolve the issue?
C:\windows\system32> nbtstat -R Successful purge and reload of the NBT remote cache table
A user was moved from one cubicle in the office to a new one a few desks over. Now, they are reporting that their VoIP phone is randomly rebooting. When the network technician takes the VoIP phone and reconnects it in the old cubicle, it works without any issues. What is the cause of the problem?
Cable short
When troubleshooting a T1 connection, the service provider’s technical support representative instructs a network technician to place a special device into the CSU/DSU. Using this device, the provider can verify that communications are reaching the CSU/DSU. What was used by the network technician?
Loopback plug
A technician receives a report that a user’s workstation is experiencing no network connectivity. The technician investigates and notices the patch cable running from the back of the user’s VoIP phone is routed directly under the rolling chair and has been repeatedly smashed. What is the likely cause of the problem?
Cross-talk
