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