ITEC 3210 Lecture Notes - Lecture 5: Network Layer
21 Oct 2021
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Next Chapter:
Transport & Network Layers
What’s Next?
In this section, info on network layer only apply to some.
Intro to routing is about finding the best path.
This doesn’t apply to access layer.
Function of Network Layer, IP or Layer 3:
IP Addressing: network layer use IP address to identify,
• Network
• Host: not the same as in application layer, here everything could be host
such as server, printer, etc.
Components of IP Address:
• Network ID
• Host ID
Versions of IP Addresses:
• IPv4: four bytes, each byte having different values, 4.4.4.4 to
255.255.255.255
• IPv6
Classes of IP Addresses:
• Class B: two left most byte for net id, two right most for the host id.
• Class A: this class will have left most part for net ID, three remaining for
host id
• Class C: three left most for net id, one right most for host id.
Document Summary
In this section, info on network layer only apply to some. Intro to routing is about finding the best path. Function of network layer, ip or layer 3: Ip addressing: network layer use ip address to identify: network, host: not the same as in application layer, here everything could be host such as server, printer, etc. Components of ip address: network id, host id. Versions of ip addresses: ipv4: four bytes, each byte having different values, 4. 4. 4. 4 to. Type of ip addresses: public: anywhere from the world is accessible, therefore its routable and possible to find best path, private: the ranges that can be used without cost, but will not help uniquely identify computer. Creating logical network where there are hosts in the same network having the same network id, or computers from different network having same network id. Benefits: better traffic management, efficient use of addresses. Disadvantage: borrowing bits from the host id to create subnet id.
