Block 9 Flashcards
DNS + purpose
Domain name server-connects domain names with any ip address
MAC address + purpose
Media access control- internal address for nic’s.
NIC
Network interface controller. Hardware that connects a device to a network
ifconfig
Shows all your network configurations
Ens5
In ifconfig. Where network info for own computer resides.
ens5 inet
Your ip address
ens5 netmask
How many hosts are available on your network
ens5 broadcast
Broadcast ip
inet6
Hex address, newer system, 128 bits
ens5 ether
Mac address
ens5 ether
Mac address
Ip address show
Show/manipulate networking interface attributes
Ping example
Ping google.com or ping 8.8.8.8
ipv4 acronym
Internet protocol version4
ip addr
Same as ipconfig
Network class A addresses and # of hosts
10.0.0.0 to 10.255.255.255. Private addresses. Millions of hosts
Network class b it’s and #of hosts
172.16 to 172.31.255.255. Private. Thousands of hosts
Network class c it’s and # of hosts
192.168 to 192.168.255.255. Private. Less than 254 hosts
etc/host
Stores local dns addresses
Curl
Basically copy url. Fetches url data from a site
Lo and lo -c
lo -c ipaddress. Check to see if we can connect to ourselves.
Ping
How many times and how many packets
Ping -c # of packets.
Ip address -c show ens5
Short way to see only ens5 data. -c shows colors
CIDR acronym and purpose
Classless inter-domain routing. Tells you how many 1s are in the subnet mask.
Ex.. 192.168
1
O/24 = 24 ones followed by 8 zeros
127.x.x.x is for what
Local hosts
Top level domain
.com, .net, etc
2nd level domain
Website name
Subdomain
Anything preceeding website name.
Ex…welcome.fullstackacademy.com
Protocol
Hotpot, https etc
nslookup
Queries dns servers to find out dns info
Non- authoritative answer in nslookup
Server had to go to another dns to find the request
Tcp
Transmission control protocol
Udp
User datagram protocol
Ports
Endpoint of network communication. Need a port to communicate. Like apartment doors in a building. Ip address is building. Port is door.
Port 20/21
File transfer protocol. 20 = data transfer, 21 = message control
Port 22
Ssh
Port 25
Simple mail transfer protocol (smtp). Emails
Port 53
Dns queries
Port 80
Http
Port 443
Https
Port 3306
Database exchange
nmap
Used to find open ports, identify devices, services and OS’s.
Sudo nmap -F 192.168.1.54
zenmap
Like nmap but gui version
netstat
Prints network stats, routing tables, interface stats.
netstat -t
Tcp ports
netstat -l
Open ports that are listening
netstat -p
Show program responsible for port
netstat -n
Show number of ports
Zenmap target
Target ip. Can use - to look @ multiple addresses.
Ex…target 192.168.2.1 -25
Network enumeration
Seeing what’s going on in the whole network.
