- the router interface for a single LAN - gives access beyond the router

- series of ones followed by series of zeroes - always totals 32 bits - one's are always the network ID, zeroes are the host ID

06 - TCP/IP Basics Flashcards by Jason Andrew

Protocols of IP

IPv4
IPv6
ICMP

How well did you know this?

Not at all

Perfectly

TCP Three-way Handshake

SYN -
SYN-ACK -
ACK -

How well did you know this?

Not at all

Perfectly

Parts of a TCP Header

Source Port
Desitnation Port
Sequence Number & ACK - keeps track of data flow
Flags - give both sides detailed info about connecttion
Checksum - checks header for errors

How well did you know this?

Not at all

Perfectly

DNS & DHCP use what protocol?

UDP

How well did you know this?

Not at all

Perfectly

How does a computer find a MAC address on the network?

Sends an ARP (Address Resolution Protocol) request to the broadcast address (FF-FF-FF-FF-FF-FF)

How well did you know this?

Not at all

Perfectly

See ARP cache in Windows?

arp -a

How well did you know this?

Not at all

Perfectly

Delete an address in ARP cache?

arp -d [address]

How well did you know this?

Not at all

Perfectly

What three things must an IP numbering system do?

create network IDs so each LAN has its own identification
Interconnect LANs using routers,
use subnet mask to determine if packet is for LAN or WAN

How well did you know this?

Not at all

Perfectly

WAN

Wide Area Network

- group of 2 or more interconnected LANs

How well did you know this?

Not at all

Perfectly

default gateway

the router interface for a single LAN

- gives access beyond the router

How well did you know this?

Not at all

Perfectly

How do routers determine where network traffic goes?

Network IDs

How well did you know this?

Not at all

Perfectly

Routing Table

instructions that tell the router what to do with incoming packets

How well did you know this?

Not at all

Perfectly

Subnet Mask

series of ones followed by series of zeroes
always totals 32 bits
one’s are always the network ID, zeroes are the host ID

How well did you know this?

Not at all

Perfectly

Whack

number of ones in an subnet mask

/24 = 24 ones

How well did you know this?

Not at all

Perfectly

Who hands out IP addresses

IANA - Internet Assigned Numbers Authority

- oversee’s 5 Regional Internet Registries (RIR)

How well did you know this?

Not at all

Perfectly

RIR for North America

ARIN - American Registry for Internet Numbers

How well did you know this?

Not at all

Perfectly

Class A network block

1-126
1.0.0.0 - 126.255.255.255
16k hosts per network ID

How well did you know this?

Not at all

Perfectly

Class B network block

128-191
128.0.0.0 - 191.255.255.255
65k hosts per network ID

Class C network Block

192-223
192.0.0.0 - 223.255.255.255
254 hosts per network ID

class D network block

224-239
224.0.0.0 - 239.255.255.255
Multicast

Class E network Block

240 - 254
240.0.0.0 - 254.255.255.255
Experimental

Difference between broadcast, unicast, multicast

broadcast - every computer on LAN gets message
unicast - message sent directly to one computer
multicast - message sent to a group of interested comptuers

octets for class network blocks

a - 0
b - 10
c - 110
d - 1110
e - 1111

CIDR

Classless Inter-Domain Routing

- breaking a single address into multiple subnets

VLSM

Variable Length Subnet Masking | -

Rules for addressing

1 - give default gateway first ip address in the network id 2 - try to use IPs in seqenctial order 3 - separate servers from clients with ranges 4 - document

Enter IP in Linux CLI

ip addr add 111.111.111.111 dev eth1 | - temporary and will be lost on reboot

Standard before DHCP

BOOTP (bootstrap protocol) | - works just like DHCP

DORA

DHCP Four Way Handshake Discover - client asks if theres any servers Offer - includes IP, subnet mask, gateway Request - server accepts offer Acknowledgement - finished

DHCP Ports

UDP 67 and 68

DHCP servers require

- legitimate pool of IP addresses to hand out (called DHCP Scope) - subnet masks for network - ip address for gateway

DHCP relay

- used when there are many LANs to route to a single DHCP server - needs real address of DHCP server to work (called IP Helper Address)

Blacklist of IPs on DHCP

IP Exclusion

MAC Reservation

DHCP assigns a specific IP address for a specific MAC address

APIPA Address

Automatic Private IP Addressing - IP address assigned when DHCP doesn't reply - generated by zero-configuration networking (zeroconf) - starts with 169.254

Release and renew IP address in Windows CLI

ipconfig /release | ipconfig /renew

Release and renew IP address in Linux CLI

sudo dhclient -r | sudo dhclient

Release and renew IP address in Mac CLI

sudo ifconfig eth0 down | sudo ifconfig eth0 up

DHCP Failover

- Has primary and secondary servers | - when one fails,the other picks up

Rogue DHCP server

a DHCP server that shoudln't be on the network

Private class A block

10.0.0.0 - 10.255.255.255

Private class B block

172.16.0.0 - 172.31.255.255

Private class C block

192.168.0.0 - 192.168.255.255

How many bits in an IPv4 address?