TCP/IP Services 7 Flashcards
What is static IP address assignment
Each node has its IP address entered manually by an administrator. If the node moves it must be manually reconfigured.
Time consuming and prone to errors. Only assigned to systems with a dedicated functionality such as routers, printers or servers that host applications
Name the two ways to assign IP address
Static and dynamic IP addressing
How can IP addresses be assigned dynamically
By using the DHCP service Dynamic Host Configuration Protocol to automatically assign IP addresses.
A DHCP server enables the scope, the range of IP addresses a subnet mask and the lease period, it automatically leases TCP/IP info to DHCP clients.
List the 4 categories of options for DHCP
Global options
Scope options
Class options
Reserved client options
What are DHCP reservations
Are lease assignments in DHCP that allow permanent IP address configuration. If case of network changes the IP address received the change when the lease is renewed.
Steps in the DHCP Lease process
Node comes online DHCP discovery DHCP offer DHCP request DHCP ACK unused DHCP offers expire
What is BOOTP
A UDP network protocol. Servers assign IP address from a pool of available address to diskless workstation (devices with no storage) computers to obtain an IP address prior to loading an advanced operating system.
What is DHCP relay agent
A service that captures BOOTP broadcast and forwards it through the router as a unicast transmission to the DHCP server on another subnet. Used if there is no DHCP server on the subnet.
What is APIPA
automatic private IP addressing
A service that enables a DHCP Client computer to configure itself automatically with an IP address in the range of 169.254.0.1 to 169.254.255.254
Not routable. Cannot communicate outside of the local subnet. Can initialize TCP/IP and communicate on the local subnet in the absence of an active DHCP Scope
What is ipconfig used for
Entered into the command prompt to display connection specific DNS suffix, IP address, subnet mask and default gateway information.
Use ipconfig /all for additional information about IP configuration
Ipconfig options for DHCP
Ipconfig /release to force release of IP address used by client
Ipconfig /renew requests renewal of an IP address for a client
The system first attempts to obtain a DHCP address and if a DHCP server fails to respond it will switch to APIPA addressing
The ping command is used for
Verifying the network connectivity of a computer. Also checks if the target system is active. Verifies the IP address, host name, and reach ability of the remote system. Uses ICMP to check the connections and listens for reply packets
What are the ping options
You can ping a computer or IP address.
The loop back address of 127.0.0.1 to test if TCP/IP has initialized on individual systems.
Other options enter ping /? at command prompt.
By default packet size are
32 bytes
To change packet size use -1 followed by packet length
What is TTL
Time to live. A value that determines how many hops an IP packet can travel before being discarded
Ping target -i TTL
Default packet count is
Four packets
Specify a night number with the -n option
Ping target -n packet count
What is ping blocking
A security measure used to block incoming packets generated by the ping command
In TCP and UDP networks a port is
The endpoint of a logical connection. All are assigned a number ranging from 0 to 65535.
Three blocks of numbers. Well known, registered, dynamic
Describe the three blocks of ports
Well known ports range from 0 to 1023
assigned for used by common service
Registered ports range from 1024 to 49151
For software makers use
Dynamic or private ports range for. 49152 to 65535
Used by unregistered services needing a temporary connection.
TCP Port 7
& UDP
Ping runs on
TCP Port 20
FTP default data runs on
TCP Port 21
FTP control runs on
TCP Port 22
& UDP
SSH runs on
TCP Port 23
& UDP
Telnet runs on
TCP Port 25
SMTP runs on
TCP Port 53
& UDP
DNS runs on
TCP Port 67
& UDP
DHCP BOOTP server runs on
TCP Port 68
& UDP
DHCP BOOTP client runs on
TCP Port 80
HTTP runs on