Pt.3 Ch.16 Networking Flashcards
What does a ping command send?
a special network packet called an ICMP ECHO_Request to a specified host
What is often times done in regard to ping for security reasons?
The network devices are configured to ignore these packets. It partially obscures a host from a potential attacker. It is also common for firewalls to be configured to block ICMP traffic.
What would pinging linuxcommand.org on the command line look like?
ping linuxcommand.org
How do you interrupt a ping packet?
Ctrl-c
What does the traceroute program do?
it lists all the “hops” network traffic takes to get from the local system to a specified host.
What information is provided by traceroute?
hostnames, IP addresses, performance data, round-trip time from the local system to the router (x3).
How do you get around being withheld information in traceroute?
traceroute -T site.com
traceroute -I site.com
What system allows us to examine a system’s network interfaces and routing table?
ip
What is the loopback interface?
lo. A virtual interface that the system uses to “talk to itself”. Found via ip a
what is eth0
The Ethernet interface
When performing casual network diagnostics, what are the important things to look for?
- the presence of the word UP in the first line for each interface (indicating that the network interface is enabled) 2. the presence of a valid IP address in the inet field on the third line 3. For system usings DHCP, a valid IP address in this field will verify that the DHCP is working.
What does DHCP stand for
Dynamic Host Configuration Protocol
What is used to examine various network settings and statistics?
netstat
How do we examine the network interfaces in our system?
netstat -ie
How do we display the kernel’s network routing table?
netstat -r