Transcript Slide 1

Chapter 7: Objectives
Part 1
 Describe the purpose of the transport layer in managing the
transportation of data in end-to-end communication.
 Describe characteristics of the TCP and UDP protocols, including
port numbers and their uses.
Part 2
 Explain how TCP session establishment and termination processes
facilitate reliable communication.
 Explain how TCP protocol data units are transmitted and
acknowledged to guarantee delivery.
 Explain the UDP client processes to establish communication with a
server.
 Determine whether high-reliability TCP transmissions, or nonguaranteed UDP transmissions, are best suited for common
applications.
1
The Transport Layer
Encapsulation
DATA
SEGMENT DATA
S.P / D.P. / S.N. / Ack # / …
DATA (SEGMENT)
PACKET
IPv / HLEN / Flag / S. IP / D. IP / …
Frame Header
FRAME
DATA
(PACKET)
Trailer
111010110101011100001001011010101010010101010101101101010001010101010110101010
3
Reminder of encapsulation/decapsulation
IP
Header
Data Link
Header
IP Packet
Data Link
Trailer
Data Link
Header
IP Packet
Data Link
Trailer
Data Link
Header
IP Packet
Data Link
Trailer
Data Link
Header
IP
Header
TCP
Header
TCP
Header
HTTP
Header
Data Link
Trailer
Data Link
Header
HTTP
Header
Data
Data
Data Link
Trailer
4
Focus on Transport Layer
TCP
TCP
5
Role of the Transport Layer
TCP UDP
 The Transport Layer is responsible for establishing a temporary
communication session between two applications and delivering
data between them.
 It regulates the flow of information from source to destination,
reliably and accurately.
6
Transport Layer Responsibility
www.cisco.com
TCP Segment
TCP Segment
TCP Segment
TCP Segment
1. Tracking the individual communication between applications on the
source and destination hosts
2. Segmenting data for manageability and reassembling segmented
data into streams of application data at the destination
3. Identifying the proper application for each communication stream
7
 What two protocols are at the Transport Layer?
 TCP
 UDP
 IP is a best-effort delivery service. What does that mean?
 No guarantees
 Best-effort service
 “Unreliable service”
 TCP/UDP is responsible for extending IP’s delivery service between two
end systems.
8
Tracking Individual Conversations
 Any host on a network can have multiple applications that are
communicating simultaneously.
 It is the responsibility of the Transport layer to maintain the
multiple communication streams between these applications.
9
HTTP
HTTP
SMTP
FTP
Cabrillo
Web
Server
TCP
TCP
TCP
TCP
TCP
TCP
ISP’s
Email
and FTP
Server
TCP
TCP
 A single client may have multiple transport connections with multiple
servers.
 Notice that TCP is a connection-oriented service (two-way arrow)
between the hosts, whereas UDP is a connectionless service (one-way
arrow) . (later)
10
Identifying the Application
11
UDP Header
TCP Header
0
15 16
16-bit Source Port Number
31
16-bit Destination Port Number
32-bit Sequence Number
32 bit Acknowledgement Number
4-bit Header
Length
6-bit
(Reserved)
U A P R S F
R C S S Y I
G K H T N N
16-bit TCP Checksum
16-bit Window Size
HTTP is Port 80
16-bit Urgent Pointer
Options (if any)
Data (if any)
 The transport layer assigns each application an identifier called a port
number.
 The transport layer uses ports to identify the application or service.
12
segment
segment
 To pass data streams to the proper applications, the Transport layer
must identify the target application.
 Accomplished by referencing the port number in the header.
 Each software process that needs to access the network is assigned
a port number unique in that host.
 This port number is used in the transport layer header to indicate
to which application that piece of data is associated.
 More later!
13
Segmenting and Reassembling Segments
 Some transport layer protocols can also reassemble the data pieces
into streams to be passed to the application layer.
14
Acronym Alert
Transport Layer Protocols
 TCP/IP uses two transport layer protocols:
 Transmission Control Protocol (TCP)
 User Datagram Protocol (UDP)
15
TCP versus UDP
TCP
UDP
 Two protocols for different types of traffic.
16
TCP Header
0
15 16
16-bit Source Port Number
31
UDP Header
16-bit Destination Port Number
32-bit Sequence Number
32 bit Acknowledgement Number
4-bit Header
Length
6-bit
(Reserved)
U A P R S F
R C S S Y I
G K H T N N
16-bit TCP Checksum
16-bit Window Size
16-bit Urgent Pointer
Options (if any)
Data (if any)
 TCP is a more complex protocol.
17
TCP Segment and UDP Datagram
18
TCP
(1943 – 1998)
Jon Postel made many
significant contributions to
the development of the
Internet, particularly in the
area of standards.
He is principally known for
being the editor of the
Request for Comment
(RFC) document series,
and for serving as the
Internet Assigned
Numbers Authority (IANA)
until his death.
 TCP is considered a reliable transport protocol.
 Introduced in RFC 793.
 It includes processes to ensure reliable delivery between.
 Analogous to sending packages using FedEx.
 With TCP, the three basic operations of reliability are:
 Tracking transmitted data segments
 Acknowledging received data
 Retransmitting any unacknowledged data
19
TCP
 The user uses FTP to upload a file to an FTP server.
20
UDP
0
15
16
31
16-bit Source Port Number
16-bit Destination Port Number
16-bit UDP Length
16-bit UDP Checksum
Data (if any)
 Providing the reliability functions of TCP also adds additional
overhead.
 UDP provides just the basic functions for delivering data segments
between the appropriate applications, with very little overhead and
data checking.
 It is known as a best-effort delivery protocol.
 Analogous to sending a regular, non-registered, letter in the mail.
21
UDP
 The user uses TFTP to upload a file to a TFTP server.
22
TCP
0
15 16
16-bit Source Port Number
31
TCP Services
16-bit Destination Port Number
32-bit Sequence Number
32 bit Acknowledgement Number
4-bit Header
Length
6-bit
(Reserved)
U A P R S F
R C S S Y I
G K H T N N
16-bit TCP Checksum
16-bit Window Size
16-bit Urgent Pointer
Options (if any)
Data (if any)
 TCP provides reliable delivery on top of unreliable IP
 In addition to supporting the basic functions of data segmentation
and reassembly, TCP also provides:






Reliable delivery
Error checking
Flow control
Congestion control
Ordered delivery
Connection establishment
24
Transmission Control Protocol (TCP)
HTTP
FTP
SMTP
 Connection-oriented protocol, described in RFC 793.
 TCP incurs additional overhead to gain functions.
 Each TCP segment adds a 20 byte header to the Application
layer data.
 Applications that use TCP include:
 Web Browsers
 E-mail
 File Transfers
 The TCP PDU is called a segment.
25
Segmenting Data
Application Data (100,000 bytes)
1-1000
TCP
1-1000
1001-2000
2001-3000
3001-4000
4001-5000
…
TCP Segment
 TCP encapsulates data into multiple segments.
 Segments are required to make network communication efficient.
 The segments header contain:
 Source port number to help keep track of individual conversations.
 Destination port number to enable a receiving host to forward the
data to the appropriate application.
 Sequence numbers help segmenting and reassembling segments.
 Window size to help with flow control.
 Error checking mechanisms.
26
Reassembling Segments
0
15 16
16-bit Source Port Number
31
16-bit Destination Port Number
32-bit Sequence Number
32 bit Acknowledgement Number
4-bit Header
Length
6-bit
(Reserved)
U A P R S F
R C S S Y I
G K H T N N
16-bit TCP Checksum
16-bit Window Size
16-bit Urgent Pointer
Options (if any)
Data (if any)
 At the receiving host, each segment is examined and reconstructed
into a complete data stream using the sequence numbers.
 Missing segments can be requested from the source.
 It is then directed to the appropriate application identified in the
segment header.
27
Same Order Delivery
 Segments can arrive out-of-order but are reorganized using
sequence numbers.
Having taken
different routes to
the destination,
the segments
arrive out of order.
NOTE:
• Establishing a Session,
Reliable Delivery, and
Flow Control will be 28
discussed later.
TCP Header
29
Source Port (16)
Destination Port (16)
Sample TCP Segment Capture
Sequence Number (32)
Acknowledgement Number (32)
Header
Length (4)
Reserved (6)
Control Bits
(6)
Checksum (16)
Window (16)
Urgent (16)
Options
Application Layer Data
30
Source Port (16)
Destination Port (16)
Sequence Number (32)
Acknowledgement Number (32)
Header
Length (4)
Reserved (6)
Control Bits
(6)
Window (16)
Checksum (16)
Urgent (16)
Options
Application Layer Data
Source Port (16 bits)
– Number of the calling port.
– Dynamically assigned to the sending host.
– Number ranges from 1024 to 65,535.
– The source port makes it possible to have multiple
sessions of FTP running simultaneously.
31
Source Port (16)
Destination Port (16)
Sequence Number (32)
Acknowledgement Number (32)
Header
Length (4)
Reserved (6)
Control Bits
(6)
Window (16)
Checksum (16)
Urgent (16)
Options
Application Layer Data
Destination Port (16 bits)
– Number of the called port.
– Sending host usually selects a number between 1 and
1023.
– End systems use the same port numbers to select the
proper application.
– E.g., when telnetting, Telnet on the source (port 23) is
talking to Telnet on the destination (port 23).
32
Source Port (16)
Destination Port (16)
Sequence Number (32)
Acknowledgement Number (32)
Header
Length (4)
Reserved (6)
Control Bits
(6)
Window (16)
Checksum (16)
Urgent (16)
Options
Application Layer Data
Sequence Number (32 bits)
– Used to establish reliability.
– Number ensures correct
sequencing of arriving data.
– Identifies the position in the
sender’s byte stream of data.
33
Source Port (16)
Destination Port (16)
Sequence Number (32)
Acknowledgement Number (32)
Header
Length (4)
Reserved (6)
Control Bits
(6)
Window (16)
Checksum (16)
Urgent (16)
Options
Application Layer Data
Acknowledgement Number (32 bits)
– Used to establish reliability.
– Next expected TCP octet.
34
Source Port (16)
Destination Port (16)
Sequence Number (32)
Acknowledgement Number (32)
Header
Length (4)
Reserved (6)
Control Bits
(6)
Checksum (16)
Window (16)
Urgent (16)
Options
Application Layer Data
Header Length (4 bits)
– Known as ʺdata offsetʺ.
– Indicates the length of the TCP segment header.
35
Source Port (16)
Destination Port (16)
Sequence Number (32)
Acknowledgement Number (32)
Header
Length (4)
Reserved (6)
Control Bits
(6)
Checksum (16)
Window (16)
Urgent (16)
Options
Application Layer Data
Control Bits (Flags) (6 bits)
– Includes bit codes, or flags, that indicate the purpose and
function of the TCP segment.
36
Source Port (16)
Destination Port (16)
Sequence Number (32)
Acknowledgement Number (32)
Header
Length (4)
Reserved (6)
Control Bits
(6)
Window (16)
Checksum (16)
Urgent (16)
Options
Application Layer Data
Window (16 bits)
– Number of octets that the receiver
is willing to accept.
– This number can be adjusted
while data is being transmitted.
37
Source Port (16)
Destination Port (16)
Sequence Number (32)
Acknowledgement Number (32)
Header
Length (4)
Reserved (6)
Control Bits
(6)
Checksum (16)
Window (16)
Urgent (16)
Options
Application Layer Data
Checksum (16 bits)
– Calculated checksum of the header and data
fields.
38
Port Numbers
UDP Header
TCP Header
0
15 16
16-bit Source Port Number
31
16-bit Destination Port Number
32-bit Sequence Number
32 bit Acknowledgement Number
4-bit Header
Length
6-bit
(Reserved)
U A P R S F
R C S S Y I
G K H T N N
16-bit TCP Checksum
16-bit Window Size
HTTP is Port 80
16-bit Urgent Pointer
Options (if any)
Data (if any)
 Both TCP and UDP use ports (or sockets) numbers to pass information to the
upper layers.
40
The application this TCP
segment came from.
The application this TCP
segment is going to.
The application this TCP
segment came from.
The application this TCP
segment is going to.
41
Port numbers are used to
by the sender to tell the
receiver which network
application it should use
for the “Data”.
Port numbers are used by
the receiver so it knows
which application it should
send the “Data” to.
Application
Header + data
Port Number
Application
Header + data
Port Number
42
http://www.iana.org/assignments/port-numbers
 TBA
 The Internet Assigned Numbers Authority (IANA) assigns port
numbers.
43
Well Known or Registered
Port Number
 Well Known Ports (Numbers 0 to 1023)
 Reserved for common services and
applications
 Client: TCP destination port
 Server: TCP source port
Well Known or Registered
Port Number
44
Well Known or Registered
Port Number
 Registered Ports (Numbers 1024 to 49151)
 Assigned to user processes or
applications.
 Non-common applications.
 Client: TCP destination port
 Server: TCP source port
 May also be used as dynamic or private
port (next).
Well Known or Registered
Port Number
45
Private/Dynamic Port
Number
Well Known or Registered
Port Number
Well Known or Registered
Port Number
Private/Dynamic Port
Number
 Dynamic or Private Ports (Numbers 49152 to 65535)
 Also known as Ephemeral Ports
 Usually assigned dynamically to client applications when initiating a
connection.
 Client: TCP source port
 Server: TCP destination port
 May also include the range of Registered Ports (Numbers 1024 to
49151)
46
Client
Server
Telnet
47
Client TCP Header
0
15 16
1028
16-bit Source Port Number
31
16-bit Destination Port Number
23
32-bit Sequence Number
32 bit Acknowledgement Number
4-bit Header
Length
6-bit
(Reserved)
U A P R S F
R C S S Y I
G K H T N N
16-bit TCP Checksum
16-bit Window Size
16-bit Urgent Pointer
Options (if any)
Data for Telnet
Data (if any)
Client
 Client sends TCP segment with:
 Destination Port: 23 (Well known port number)
 Source Port: 1028 (Dynamic Port assigned by client)
Server
48
Server TCP Header
15 16
0
23
16-bit Source Port Number
31
16-bit Destination Port Number
1028
32-bit Sequence Number
32 bit Acknowledgement Number
4-bit Header
Length
6-bit
(Reserved)
U A P R S F
R C S S Y I
G K H T N N
16-bit TCP Checksum
16-bit Window Size
16-bit Urgent Pointer
Options (if any)
Data for Telnet
Data (if any)
Client
 Server responds with TCP segment with:
 Destination Port: 1028 (Dynamic Port assigned by client)
 Source Port: 23 (Well known port number)
Server
49
Notice the difference in how source and destination port numbers are
used with clients and servers:
Client (initiating Telnet service):
 Destination Port = 23 (telnet)
 Source Port = 1028 (dynamically assigned)
Server (responding to Telnet service):
 Destination Port = 1028 (source port of client)
 Source Port = 23 (telnet)
50
49888
49890
 Same client to same server - Two different HTTP sessions
 Client: Same destination port
 Client: Different source ports to uniquely identify this web session.
51
49888
49890
C:\Users\rigrazia>netstat -n
Active Connections
TCP
or
UDP
Proto
TCP
TCP
Source Port
Local Address
192.168.1.101:49888
192.168.1.101:49890
C:\Users\rigrazia>
Destination Port
Foreign Address
198.133.219.25:80
198.133.219.25:80
Source IP
Connection State
State
TIME_WAIT
TIME_WAIT
Destination IP
52
192.168.1.101
Source
Port
49888
49890
Destination
Port
198.133.219.25
80
80
80
172.16.5.5
Source
Port
49888
www.cisco.com
What makes each connection unique? How does the server know
which source port 49888 is who?
 Connection defined by the pair of numbers:
 Source IP address, Source port (From Client to Server)
 Destination IP address, Destination port (From Server to
Client)
 Different connections can use the same destination port on server
host as long as the source ports or source IPs are different.
53
Sockets
192.168.1.101
Source
Port
49888
Destination
Port
198.133.219.25
80
www.cisco.com
 Combining the transport layer port number and the network layer IP
address uniquely identifies a particular application process running
on an individual host device.
 This combination is called a socket.
 A socket pair, consisting of the source and destination IP addresses
and port numbers, is also unique and identifies the specific
conversation between the two hosts.
54
Socket Port Number Example
192.168.1.101
Source
Port
49888
Destination
Port
198.133.219.25
80
www.cisco.com
 A client socket might look like this, representing the source IP
address and source port number:
 192.168.1.101:49888
 The socket on a web server might be, representing the destination
IP address and destination port number:
 192.133.219.25:80
 Together, these two sockets combine to form a socket pair:
 192.168.1.101:49888, 192.133.219.25:80
55
TCP
or
UDP
Connection State
Source IP
Destination IP
Source Port
Destination Port
www.google.com
www.cisco.com
netstat –n
 Note: When downloading a web document and its objects it is common that
there will be several TCP sessions created.
56
Client Requesting a Webpage
57
Server Replying to the Client
58
Socket Port Number Example
So who makes sure that
applications are
assigned a specific port
number?
59
Port Numbers
 The Internet Assigned Numbers Authority (IANA) assigns port
numbers.
 The IANA is a standards body that is responsible is responsible
for the global coordination of the DNS Root, IP addressing, and
other Internet protocol resources
 Port numbers range from 0 to 65535 (16 bits).
 There are three categories of port numbers:
 Well Known Ports
(0 – 1023)
 Registered Ports
(1024 – 49151)
 Private and/or Dynamic Ports (49152 – 65535)
60
Well Known or Registered
Port Number
 Well Known Ports (Numbers 0 to 1023)
 Reserved for common services and
applications
 Client: TCP destination port
 Server: TCP source port
Well Known or Registered
Port Number
61
Well Known or Registered
Port Number
 Registered Ports (Numbers 1024 to 49151)
 Assigned to user processes or
applications.
 Non-common applications.
 Client: TCP destination port
 Server: TCP source port
 May also be used as dynamic or private
port (next).
Well Known or Registered
Port Number
62
Private/Dynamic Port
Number
Well Known or Registered
Port Number
Well Known or Registered
Port Number
Private/Dynamic Port
Number
 Dynamic or Private Ports (Numbers 49152 to 65535)
 Also known as Ephemeral Ports
 Usually assigned dynamically to client applications when initiating a
connection.
 Client: TCP source port
 Server: TCP destination port
 May also include the range of Registered Ports (Numbers 1024 to
49151)
63
Transport Layer Port Numbers









Hypertext Transfer Protocol (HTTP) - TCP Port 80
HTTP Secure (HTTPs)
- TCP Port 443
Simple Mail Transfer Protocol (SMTP)
- TCP Port 25
Post Office Protocol (POP)
- TCP Port 110
Telnet
- TCP Port 23
File Transfer Protocol (FTP)
- TCP Ports 20 & 21
Trivial FTP (TFTP)
- UDP 69
Domain Name System (DNS)
- TCP/UDP Port 53
Dynamic Host Configuration Protocol
- UDP Port 67 & 68
http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers
64
TCP/IP Application Layer Protocols
Application
Layer
Transport
Layer
Internet
Layer
Network
Access
Layer
FTP
HTTP
SMTP
Telnet
TFTP
SNMP
DHCP
DNS
20 & 21
80
25
23
69
161
67 & 68
53
TCP
UDP
IP
LAN / WAN
65
Which Connections Are Open on a Host?
Apples-MacBook-Pro:~ rigrazia$ netstat
Active Internet connections
Proto Recv-Q Send-Q Local Address
tcp4
0
0 10.0.0.108.54500
tcp4
0
0 10.0.0.108.54485
tcp6
0
0 2601:9:6800:1e6:.54455
tcp6
0
0 2601:9:6800:1e6:.54419
tcp6
0
0 2601:9:6800:1e6:.54400
tcp4
0
0 10.0.0.108.54385
tcp4
0
0 10.0.0.108.54368
tcp6
0
0 2601:9:6800:1e6:.54297
tcp4
0
0 10.0.0.108.53964
tcp4
0
0 10.0.0.108.53939
tcp4
0
0 10.0.0.108.53913
tcp4
0
0 10.0.0.108.53836
tcp4
0
0 localhost.49961
tcp4
0
0 localhost.53264
tcp4
0
0 localhost.49961
tcp4
0
0 localhost.53263
tcp4
0
0 10.0.0.108.52960
tcp4
0
0 10.0.0.108.50737
tcp4
0
0 10.0.0.108.62510
tcp4
0
0 10.0.0.108.62508
Foreign Address
a184-51-102-51.d.http
g1.v.fwmrm.net.http
nuq05s01-in-x11..https
edge-star6-shv-0.https
2001:559:0:54::6.https
a184-51-102-42.d.http
a184-84-222-181..macro
nuq05s02-in-x01..https
valiente.cabrill.ssh
valiente.cabrill.ssh
gw094.lphbs.com.http
68.71.212.186.http
localhost.53264
localhost.49961
localhost.53263
localhost.49961
channelproxy-shv.https
boris.cabrillo.e.imaps
boris.cabrillo.e.imaps
boris.cabrillo.e.imaps
(state)
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
CLOSE_WAIT
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
 Sometimes it is necessary to know which active TCP connections are
open and running on a networked host.
 Netstat is a network utility that can be used to verify those
connections.
 It lists the protocol in use, the local address and port number, the
foreign address and port number, and the state of the connection.
66
Netstat
Apples-MacBook-Pro:~ rigrazia$ netstat
Active Internet connections
Proto Recv-Q Send-Q Local Address
tcp4
0
0 10.0.0.108.54500
tcp4
0
0 10.0.0.108.54485
tcp6
0
0 2601:9:6800:1e6:.54455
tcp6
0
0 2601:9:6800:1e6:.54419
tcp6
0
0 2601:9:6800:1e6:.54400
tcp4
0
0 10.0.0.108.54385
tcp4
0
0 10.0.0.108.54368
tcp6
0
0 2601:9:6800:1e6:.54297
Foreign Address
a184-51-102-51.d.http
g1.v.fwmrm.net.http
nuq05s01-in-x11..https
edge-star6-shv-0.https
2001:559:0:54::6.https
a184-51-102-42.d.http
a184-84-222-181..macro
nuq05s02-in-x01..https
(state)
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
CLOSE_WAIT
ESTABLISHED
ESTABLISHED
 Unexplained TCP connections can pose a major security threat.
 This is because they can indicate that something or someone is
connected to the local host.
 Additionally, unnecessary TCP connections can consume valuable
system resources thus slowing down the host's performance.
 Netstat can be used to examine the open connections on a host
when performance appears to be compromised.
 Netstat Security Podcast
 TCPView
67
C:\Users\Admin> netstat /?
Displays protocol statistics and current TCP/IP network connections.
NETSTAT [-a] [-b] [-e] [-f] [-n] [-o] [-p proto] [-r] [-s] [-t] [interval]
-a
-b
-e
-f
-n
-o
-p proto
-r
-s
-t
interval
C:\Users\Admin>
Displays all connections and listening ports.
Displays the executable involved in creating each connection or
listening port. In some cases well-known executables host
multiple independent components, and in these cases the
sequence of components involved in creating the connection
or listening port is displayed. In this case the executable
name is in [] at the bottom, on top is the component it called,
and so forth until TCP/IP was reached. Note that this option
can be time-consuming and will fail unless you have sufficient
permissions.
Displays Ethernet statistics. This may be combined with the -s
option.
Displays Fully Qualified Domain Names (FQDN) for foreign
addresses.
Displays addresses and port numbers in numerical form.
Displays the owning process ID associated with each connection.
Shows connections for the protocol specified by proto; proto
may be any of: TCP, UDP, TCPv6, or UDPv6. If used with the -s
option to display per-protocol statistics, proto may be any of:
IP, IPv6, ICMP, ICMPv6, TCP, TCPv6, UDP, or UDPv6.
Displays the routing table.
Displays per-protocol statistics. By default, statistics are
shown for IP, IPv6, ICMP, ICMPv6, TCP, TCPv6, UDP, and UDPv6;
the -p option may be used to specify a subset of the default.
Displays the current connection offload state.
Redisplays selected statistics, pausing interval seconds
between each display. Press CTRL+C to stop redisplaying
statistics. If omitted, netstat will print the current
configuration information once.
68
C:\Users\Admin>netstat
Active Connections
Proto
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
TCP
Local Address
127.0.0.1:5354
127.0.0.1:5354
127.0.0.1:19872
127.0.0.1:27015
127.0.0.1:49155
127.0.0.1:49156
127.0.0.1:49168
127.0.0.1:49172
192.168.1.116:2869
192.168.1.116:49826
192.168.1.116:49828
192.168.1.116:49950
192.168.1.116:50010
192.168.1.116:50011
192.168.1.116:50012
192.168.1.116:50013
[::1]:49772
[::1]:49774
Foreign Address
Admin-PC:49155
Admin-PC:49156
Admin-PC:49172
Admin-PC:49168
Admin-PC:5354
Admin-PC:5354
Admin-PC:27015
Admin-PC:19872
Home-Net:42808
www.cisco.com:http
17.172.232.124:5223
17.158.10.21:https
ec2-204-236-229-250:http
ec2-204-236-229-250:http
ec2-204-236-229-250:http
ec2-204-236-229-250:http
Admin-PC:49774
Admin-PC:49772
State
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
ESTABLISHED
TIME_WAIT
ESTABLISHED
ESTABLISHED
CLOSE_WAIT
TIME_WAIT
TIME_WAIT
ESTABLISHED
TIME_WAIT
ESTABLISHED
ESTABLISHED
C:\Users\Admin>
69