Which of the following is a classful routing protocol?

A.
RIPv1

B.
EIGRP

C.
BGPv4

D.
RIPv2

Explanation:
The Routing Information Protocol version 1 (RIPv1) is a classful routing protocol, which exchanges routes
without including any subnet masking information. IP addresses in the routing table should have the samesubnet mask. Because classful routing protocols may not fully utilize the available IP address range, all router
interfaces within the same network must have the same subnet mask.
Open Shortest Path First (OSPF), Routing Information Protocol version 2 (RIPv2), Enhanced Interior Gateway
Routing Protocol (EIGRP), and Border Gateway Protocol version 4 (BGPv4) are classless routing protocols.
These protocols include the subnet mask in the route advertisement and support variable length subnet masks
(VLSM). Intermediate System-to-Intermediate System (IS-IS) is also a classless routing protocol. An example
of a network using VLSM is shown below. Note the different masks used, indicated with CIDR notation.

Objective:
Routing Fundamentals
Sub-Objective:
Compare and contrast distance vector and link-state routing protocols

Cisco > Articles > Cisco Networking Academy > CCNP 1: Advanced IP Addressing Management
Cisco > Internetworking Technology Handbook > Routing Information Protocol (RIP)