IPv6
-128 bits in length
-Use Hexadecimal (4bits)
Segment = 4 hexadecimal (16bits)
-Use shorthand notation:
2018:0000:0000:0000:4815  2018:0:0:0:4815  2018::4815
3 types of IPv6:
Unicast Address: used to identify a single interface. Globally routed and link-local.
Multicast Address: used to identify a set of interfaces and begins with FF.
Anycast Address: used to identify a set of interfaces so that packets can be sent to any member
of a set.
Globally-routed: IPv6 address that starts with 2000-3999
Link-local: ipv6 address that starts with FE80
SLAAC (stateless address autoconfiguration) : eliminates the need to obtain addresses or other
configuration information from a central server.
EUI (extended unique identifier): allows host to assign itself a unique 64-bit IPv6 interface
identifier called EUI-64
NDP (neighbor discovery protocol) : Used for neighbor discovery in IPv6. Used to determine
layer 2 address that are on a given network.
DHCPv6: DHCP that chooses address from IPv6 address server
Address exhaustion : running out of IPv4 addresses
Dual stack: simultaneously runs both IPv4 and IPv6 protocols on the same network devices
Tunneling: allows an existing IPv4 router to carry IPv6 traffic
PORTS AND PROTOCOLS
***MEMORIZE ENTIRE SECTION
Port: logical communication endpoint that exists on a computer or server
Inbound port: port opening on a server that is listening for a connection from a client
Outbound port: port opening created on a client in order to call out to a server that is listening
for a connection.
Ports range : (0, 65535)
Well known ports: [0, 1023], considered well-known and are assigned by IANA.
Registered ports: [1024, 49151], considered registered and usually assigned propriety protocols
- Port 1433 = SQL
- Port 3389 = RDP
Dynamic/Private Ports: [49152, 65535], can be used by any application without being registered
with IANA. Commonly used in gaming and instant chat.
FTP (File transfer protocol) : provides insecure file transfers. Ports 20, 21
TFTP (trivial file transfer protocol): connectionless protocol that uses UDP as its transport.
Port 69.
SSH (secure shell): provides secure remote control of another machine using a text-based
environment. Port 22.
SFTP (secure file transfer protocol) : provides secure file transfers using encryption. Port 22.
Telnet: insecure remote access via command prompt. Port 23
SMTP (simple mail transfer protocol) : provides ability to send emails over network. Port 25.
DNS: Converts domain names to IP address, and vice versa. Port 53
DHCP: automatically assign IP addresses. Port 67, 68
HTTP: insecure web browsing. Port 80
POP3 (post office protocol version three): used for receiving incoming emails. Port 110
NetBIOS (network basic i/o system): file or printer sharing in Windows network. Port 137, 139
IMAP (internet mail application protocol): newer method of retrieving incoming emails.
Improvement of POP3. Port 143
SNMP (simple network management protocol): used to collect data about network devices and
their status. Port 161, 162
LDAP (lightweight directory access protocol): directory service for your network. Port 389
HTTPS (hypertext transfer protocol-secure) : secure and encrypted version of HTTP. Uses SSL
and TLS for security and encryption. Port 443
SMB (server message block) : provide shared access for files and printer sharing. Port 445
RDP (remote desktop protocol): provide GUI remote control of another client or server. Port
3389
TCP vs UDP
TCP: connection-oriented protocol. Reliable way of transporting segments across networks.
UDP: connectionless protocol. unreliable and transmits segments called datagram
TCP
Reliable (3 way handshake)
Connection-oriented
Segment retransmission & flow control
(windowing)
With segmentation of sequencing
With acknowledgement
Examples:
SSH, HTTP. HTTPS
UDP
Not reliable
Connectionless
No retransmission & no windowing
Without sequencing
Without acknowledgement
Example:
Audio/Video streaming, DHCP, TFTP