Index

COMPUTER NETWORKING

  1. INTRO
    1. TCP/IP Five Layer Model
    2. NETWORKING DEVICES
    3. PHYSICAL LAYER
    4. DATALINK LAYER
  2. NETWORK LAYER
    1. IP
    2. SUBNET
    3. ROUTING
  3. TRANSPORT & APPLICATION LAYER
    1. TRANSPORT LAYER
    2. CONTROL FLAGS
    3. APPLICATION LAYER
    4. ALL TOGETHER
  4. NETWORK SERVICES
    1. DNS - NAMES RESOLUTION
    2. DHCP
    3. NAT
    4. VPN
  5. CONNECTING TO INTERNET
    1. BROADBAND
    2. WAN
    3. WIRELESS NETWORKING
  6. TROUBLESHOOTING
  7. MORE ABOUT
    1. DNS
    2. IPv6
    3. CLOUD

TROUBLESHOOTING

Error-detection
Error-recovery

Verifying

Connectivity

:


ICMP : Internet Control Message Protocol
images/26-1.png

Ping : lets u send a special type of ICMP message called an Echo Request(asks the destination if its there, destination sends echo reply).
images/26-2.png


TraceRoute

:


A utility lets u discover the path between two nodes, and gives u information about each hop along the way.
ICMP time exceeded messade
for each route- 3 packets.
images/26-3.png
tracert in windows

Long running traceroutes:
mtr - Linux/MacOS
pathping - Windows

images/26-4.png


Testing

Port

Connectivity

:


Problems in the transport layer.
Tools:
netcat - linux/macOS
Test-NetConnection - Windows

Send application layer data to the listening server