Network + Part 3

0.0.0.0 - 127.255.255.255

128.0.0.0 to 191.255.255.255

192.0. 0.0 through 223.255.255.0

When a device changes an IP address as it is communicating through a network. Assigned at the router. Goes from a private to a public IP address.

Port address translation. Allows multiple IP addresses to use a single NAT IP address through a router.

One station sends information to another station. One to one.

1 source device that sends out the packet to everyone connected on the network. Used in IPv4. Has performance issues with many devices connected to the network.

Delivery of information to any interested systems. Used in IPv4 and mostly in IPv6

Single destination IP address has multiple paths to 2 or more endpoints. Sends to 1 device which relays the packet to others. Used in IPv4 and IPv6.

128 bit address with 340 undecillion addresses. Shown as a hexadecimal.

• Groups of zeros can be abbreviated with a double colon. However, only one of these abbreviations are allowed per address.
• Leading zeros are optional.

2600:DDDD:1111:1::1

Static IP addressing with IPv6. Extended Unique Identifier. Combined the MAC address with the IPv6 address.

Media Access Control Address. On the physical network adapter. The first 3 sections are the manufacturer. The last 3 sections are the serial number. Also known as an EUI-48, Extended Unique Identifier with 48 bits.

• Split the MAC address into two 24 bit halves.
• Put FFFE in the middle for the missing 16 bits.
• Invert the seventh bit. 0 to 1 and vice versa.

• Flipping the 7th bit

• 0	1
  2	3
  4	5
  6	7
  8	9
  A	B
  C	D
  E	F

8e2d:aaff:fe4b:98a7

Internet Assigned numbers Authority. Provides address blocks to RIRs

Regional Internet Registries. RIR assigns smaller subnet blocks to ISPs. The ISP assigns a /48 subnet to the customer.

Sends IPv6 over an existing IPv4 Network. Creates an IPv6 address based on the IPv4 address. Requires relay routers. No support for NAT. Network Address Translation.

Tunnel IPv4 traffic on an IPv6 network.

Tunnels IPv6 through a NATed IPv4 network. No special IPv6 router needed.

Run both IPv4 and IPv6 at the same time. Interfaces will be assigned multiple address types. Separate configurations.

Address Resolution Protocol (ARP) is a protocol or procedure that connects an ever-changing Internet Protocol (IP) address to a fixed physical machine address, also known as a media access control (MAC) address, in a local-area network (LAN). Similar to DHCP. This is for IPv4 Only.

Replaces ARP for IPv6. Allow computers a way to find each other on the network.

Stateless Address Autoconfiguration. Automatically configure an IP address without a DHCP server. Uses EUI-64, Extended unique identifier, in an IPv6 network.

Duplicate Address Detection for IPv6.

Contains the Header, IP, TCP/UDP port Number, Ethernet Payload, Ethernet Trailer.

Allows the use of many different applications at the same time. TCP and UDP can both be encapsulated by the IP protocol. Moves on the Lay 4 Transport Layer.

• Transmission Control Protocol
• Connection Oriented. Reliable in the sense it can recover from errors and orders messages. Allows for flow control

User Datagram Protocol. Connectionless, there is no error recovery or ordering of data. No flow control. The receiver does not talk back to the sender.

Port Numbers

• tcp/23
• Console access from another device. Unencrypted.

• TCP/22
• Secure Shell. Encrypted version of Telnet.

• UDP/53
• Domain Name System. Converts names to IP addresses.
• Large transfers may use TCP/53

• tcp/25 – SMTP using plaintext
• tcp/587 – SMTP using TLS encryption
• Simple Mail Transfer Protocol.
• Server to server email transfer. SENDS MAIL. IMAP and POP3 are for inbound.

• tcp/110 plaintext
• tcp/995 POP over TLS
• Receive emails from an email server. Can authenticate and transfer.

• tcp/143 plaintext
• tcp/993 IMAP over TLS
• Internet Message Access Protocol. Includes management of email inbox from multiple clients. Receives.

• Secure File Transfer Protocol
• tcp/22 -Uses the SSH File Transfer Protocol
• Provides file system functionality. Resuming interrupted transfers, directory listings, remote file removal.

• File Transfer Protocol
• tcp/20 for active mode data
• tcp/21 for control
• Transfers files between systems. Authenticates with a username and password. Full functionality such as list, add, delete.

• Trivial File Transfer Protocol
• udp/69
• Very simple file transfer application. Can read and write files. No Authentication. Not used in production systems.

• Dynamic Host Configuration Protocol
• udp/67
• udp/68
• Automatic configuration of IP address subnet mask and other options. Requires a DHCP server. IP addresses can be dynamic, pulled from a pool, or reserved for a specific MAC address.

• Hypertext Transfer Protocol
• tcp/80
• Communication in the browser and through applications. Web server communication.

• Hypertext Transfer Protocol Secure
• tcp/443
• Uses TLS (Transport Layer Security)(Current) or SSL(Secure Sockets Layer)(Outdated). Provides web server communication with encryption.

• Simple Network Management Protocol
• udp/161
• Gather stats from network devices. Version 3 has message integrity, authentication, and encryption.

• Simple Network Management Protocol Trap.
• udp/162
• Alerts and notifications from the network devices.

• udp/514
• Standard for message logging for diverse systems. Uses a SIEM (Security Information Event Manager).

• Remote desktop protocol
• tcp/3389
• Shares a desktop from a remote location.

• Network Time Protocol
• udp/123
• Sends clock information to every device

• Session Initiation Protocol
• tcp/5060
• tcp/5061
• Voice over IP VOIP

• Server Message Block Common Internet File System
• tcp/445
• Windows protocol for file sharing, printer sharing.

• Lightweight Directory Access Protocol
• tcp/389
• Store and retrieve information in a network directory. Used to keep track of users.

• Lightweight Directory Access Protocol Secure
• tcp/636
• LDAP over SSL
• Store and retrieve information in a network directory. Used to keep track of users.