The difference between class-and no-class routing

Recently saw the RIP and OSPF aspects. Both protocols are divided within NA as the distance vector routing protocol and the link state routing protocol. But there is a way to divide the routes in NP based on the class routing protocol and the class-free routing protocol.

RIP is based on a routing protocol with classes, and OSPF is a non-class routing protocol.

A class-aware route does not recognize the subnet's information, such as declaring 10.0.1.0/24 172.16.1.0/22 192.168.1.64/28 only the Class A 10.0.0.0/8 is recognized in the routing table,
Class B 172.16.0.0/16 Class C 192.168.1.0/24

A class-free routing protocol is not recognized according to a B class C, and distinguishes the network segment based on the length of the subnet mask, so no class routing protocol can support automatic routing summarization.

There are classes of routes that naturally do not support VLSM class-free routing to support VLSM

IP routing protocol can be divided into two categories, one is class, the other is non-class.

IP classful
RIP v1, IGRP, EGP

IP classless
RIP v2, EIGRP, OSPF, Is-is, BGP

A routing protocol with a class only transmits a network prefix (network address), but does not contain a subnet mask. When it transmits an update, it first checks whether the directly connected network is the same larger subnet as the network that is sending the update, and if so, it continues to check that their subnet masks are equal, and if not, the updated information is discarded without being broadcast.

When router A sends an update to Router B, it follows these steps:
1. Router A checks to see if the 192.168.1.0/24 and 192.168.2.0/30 (the network that updates the pass-through) belong to the same larger subnet.
2. The answer is yes, so router a compares their subnet masks 192.168.1.0/24 and 192.168.2.0/30.
3. Because they have two different subnet masks, the information is discarded.
This is why there is a class routing protocol that does not support VLSM (variable eldest subnet mask)

The No-class routing protocol transmits a network prefix (network address) and also transmits a subnet mask, so it supports VLSM

There are class address: The early IP address has no subnet mask, all the addresses belong to the corresponding main class network, the distance vector routing protocol such as Rip1,igrp belongs to a class of routing protocol, it can not learn from the neighbors of the subnet, all about the subnet of the route is learned automatically converted to the corresponding main class network. For example, 182.16.1.0 will become the Class B address of the main class network 182.16.0.0.
No-class Address: Divides different networks according to the subnet mask of variable length. For example, 182.16.1.101, there are classes where the subnet segment is 182.16.0.0, subnet mask 255.255.0.0, now the subnet mask is changed to 255.255.255.252 30-bit mask, where the subnet segment is 182.16.1.100. Routing protocols that support variable-length subnet masks are RIP2,OSPF and EIGRP.

The difference between class-and no-class routing