Chapter 10 Troubleshooting Networking & Security Issues Flashcards
When configuring the network interface on a Windows server, what is the term used to designate the IP address of the router interface on the local subnet?
Default gateway
The term default gateway can be misleading since a gateway is now called a router. But a default gateway is the IP address on the interface on the router on the local subnet that connects to the outside world. It gives computers on one network a path to other networks.
Chapter 10 (page 292)
What determines the size of a group of servers sharing the same network range?
Subnet mask
The mask determines the total number of hosts on each network. All hosts will contain this mask information to determine which network they are on. The subnet masks must exactly match, or you will have network connectivity problems with the incorrectly configures resources.
Chapter 10 (page 291)
Which text-based remote access application is used to securely access Linux servers in a public cloud?
SSH
Secure Shell (SSH) is the encrypted version of the Telnet protocol and is used to access remote devices using a command-line interface. Use port 22 for communications.
Chapter 10 (page 305)
Scott is troubleshooting a SQL access issue and wants to look at the data frames being sent and received from his network adapter card on the Linux database server. What utility would he use to collect the traces?
tcpdump
tcpdump allows Linux system to capture live network traffic and is useful in monitoring and troubleshooting. Sometimes called sniffing, tcpdump allows you to set up filters to select the traffic you are interested in capturing for troubleshooting. Think of tcpdump as a command-line network analyzer.
Chapter 10 (page 305)
A remote user is unable to reach a Linux-based web server hosted in the Singapore zone of the cloud provider. The user is located in Austin, Texas. What utility can she use to verify the connection path?
traceroute
The tracert/traceroute utilities are useful for network path troubleshooting. The traceroute utility displays the routed path a packet of data takes from source to destination. You can use it to determine whether routing is working as expected or whether there is a route failure in the path.
Chapter 10 (page 306)
A Cloud+ student you are mentoring asks about the mappings between the layer 2 MAC address and the gateway router’s IP address. He wants to verity that the VM has the correct network mapping information. Which utility would you tell him to use to gather this information?
ARP
Address Resolution Protocol (ARP) is the protocol that determines the mapping of the IP address to the physical MAC address on a local network.
Using ARP, all devices on the LAN build a table of IP to MAC address bindings.
Chapter 10 (page 298)
You are configuring a remote out-of-band management network that connects to router and switch serial ports in a private cloud. What product would you need to install to accomplish this task?
terminal server
In a data center, devices called terminal servers are deployed that have several serial ports, each cabled to a console port on a device that is being managed. This allows you to make an SSH or a Telnet connection to the terminal server and then use the serial interfaces to access the console ports on the devices you want to connect to.
Chapter 10 (page 307)
What Window server application presents the server’s graphical desktop on a remote user’s screen?
Remote Desktop Services
Remote Desktop Services (RDP) allows remote access to Windows devices. RDP is a client-server application, which means RDP has to be installed and running on both the server and the local workstation you are using to access the cloud server. The desktop application comes preinstalled on most versions of Windows.
Chapter 10 (page 309)
To verify network reachability from a NoSQL database server residing in a private subnet on a public cloud to the application tier, what utility can she use as a quick connectivity test?
ping
ping is part of the TCP/IP family of protocols; it is used to verify that a device is available and reachable on the network and also to get a reading of the response time at the moment in time.
Chapter 10 (page 303)
After deploying a new public website, your validation steps ask you to check the domain name to IP address mappings. What Linux and Windows utilities can be used for validation?
dig and nslookup
nslookup and dig are command-line utilities used to resolve hostnames to IP addresses using a DNS server. nslookup is the Windows variant and its Linux equivalent is called dig. If you need to learn the IP address of a domain, use these applications to resolve the DNS name to the IP address.
Chapter 10 (page 302)
Sarah made an SSH connect to a remote bastion host. She needs to add an access control list rule to allow the bastion server to access a new subnet. She needs the source IP address of her host. What command can she run on the server to collect this information?
ifconfig
ifconfig on Linux and ipconfig on Windows are command-line utilities used to verify and configure the local network interfaces.
Chapter 10 (page 300)
The ____ network utility is found in both Windows and Linux operating systems and is used to show what network connection are open to remote applications.
netstat
netstat is a network statistic utility found on both Windows and Linux workstation and servers. You can use netstat when troubleshooting to see which network connections are open to remote applications, to view detailed protocol information, to see addresses used both locally and remotely, and to determine which state the TCP connections are currently in on the device.
Chapter 10 (page 300)
The ____ network utility is found in both Windows and Linux operating systems and is used to show what network connection are open to remote applications.
netstat
netstat is a network statistic utility found on both Windows and Linux workstation and servers. You can use netstat when troubleshooting to see which network connections are open to remote applications, to view detailed protocol information, to see addresses used both locally and remotely, and to determine which state the TCP connections are currently in on the device.
Chapter 10 (page 300)
Both the Linux ____ and the Windows ____ utilities query a DNS system, giving a domain name and receiving the corresponding IP address.
dig
nslookup
nslookup is the Windows variant, and dig is the Linux equivalent, command-line utilities used to resolve hostnames to IP addresses using a DNS server. If you need to learn the IP address of a domain, use these applications to resolve the DNS name to the IP address.
Chapter 10 (page 302)
Both the Linux ____ and the Windows ____ utilities query a DNS system, giving a domain name and receiving the corresponding IP address.
dig
nslookup
nslookup is the Windows variant, and dig is the Linux equivalent, command-line utilities used to resolve hostnames to IP addresses using a DNS server. If you need to learn the IP address of a domain, use these applications to resolve the DNS name to the IP address.
Chapter 10 (page 302)