© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
ITE PC v4.0
Chapter 1 1
RIPv2
Routing Protocols and
Concepts – Chapter 7
ITE PC v4.0
Chapter 1 2© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Objectives
 Encounter and describe the limitations of RIPv1’s
limitations.
 Apply the basic Routing Information Protocol Version
2 (RIPv2) configuration commands and evaluate
RIPv2 classless routing updates.
 Analyze router output to see RIPv2 support for VLSM
and CIDR
 Identify RIPv2 verification commands and common
RIPv2 issues.
 Configure, verify, and troubleshoot RIPv2 in “handson”
labs
ITE PC v4.0
Chapter 1 3© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Introduction
 Chapter focus
-Difference between RIPv1 & RIPv2
RIPv1
-A classful distance vector routing protocol
-Does not support discontiguous subnets
-Does not support VLSM
-Does not send subnet mask in routing update
-Routing updates are broadcast
RIPv2
-A classless distance vector routing protocol that is an
enhancement of RIPv1’s features.
-Next hop address is included in updates
-Routing updates are multicast
-The use of authentication is an option
ITE PC v4.0
Chapter 1 4© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Introduction
 Similarities between RIPv1 & RIPv2
-Use of timers to prevent routing loops
-Use of split horizon or split horizon with poison
reverse
-Use of triggered updates
-Maximum hop count of 15
ITE PC v4.0
Chapter 1 5© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
RIPv1 Limitations
 Lab Topology
 Scenario:
3 router set up
Topology is discontiguous
There exists a static summary
route
Static route information can be
injected into routing table updates
using redistribution.
Routers 1 & 3 contain VLSM
networks
ITE PC v4.0
Chapter 1 6© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
RIPv1 Limitations
 Scenario Continued
 VLSM
-Recall this is sub netting
the subnet
 Private IP addresses are
on LAN links
 Public IP addresses are
used on WAN links
 Loopback interfaces
-These are virtual
interfaces that can be
pinged and added to
routing table
ITE PC v4.0
Chapter 1 7© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
RIPv1 Limitations
 Null Interfaces
This is a virtual interface that does not need to be
created or configured
-Traffic sent to a null interface is discarded
-Null interfaces do not send or receive traffic
 Static routes and null interfaces
null interfaces will serve as the exit interface for
static route
-Example of configuring a static supernet route with a
null interface
-R2(config)#ip route 192.168.0.0 255.255.0.0 Null0
ITE PC v4.0
Chapter 1 8© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
RIPv1 Limitations
 Route redistribution
-Redistribution command is way to disseminate a
static route from one router to another via a routing
protocol
-Example
R2(config-router)#redistribute static
ITE PC v4.0
Chapter 1 9© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
RIPv1 Limitations
 Verifying and Testing Connectivity
Use the following commands:
 show ip interfaces brief
 ping
 traceroute
ITE PC v4.0
Chapter 1 10© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
RIPv1 Limitations
 RIPv1 – a classful routing protocol
-Subnet mask are not sent in updates
-Summarizes networks at major network boundaries
-if network is discontiguous and RIPv1 configured
convergence
will not be reached
ITE PC v4.0
Chapter 1 11© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
RIPv1 Limitations
Examining the routing tables
-To examine the contents of
routing updates use the
debug ip rip command
-If RIPv1 is
configured then
Subnet masks will not be
included with the
network address
ITE PC v4.0
Chapter 1 12© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
RIPv1 Limitations
 RIPv1 does not support
VLSM
Reason: RIPv1 does not
send subnet mask
in routing updates
 RIPv1 does summarize
routes to the Classful
boundary
Or uses the Subnet mask
of the outgoing interface
to determine which
subnets to advertise
ITE PC v4.0
Chapter 1 13© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
RIPv1 Limitations
 No CIDR Support
 In the diagram R2 will not
include the static route in its
update
Reason: Classful routing
protocols do not support
CIDR routes that are
summarized with a smaller
mask than the classful
subnet mask
ITE PC v4.0
Chapter 1 14© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Configuring RIPv2
 Comparing RIPv1 & RIPv2 Message Formats
-RIPv2 Message format is similar to RIPv1 but has 2
extensions
1st extension is the subnet mask field
2nd extension is the addition of next hop
address
ITE PC v4.0
Chapter 1 15© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Configuring RIPv2
 Enabling and Verifying RIPv2
 Configuring RIP on a Cisco router
By default it is running RIPv1
ITE PC v4.0
Chapter 1 16© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Configuring RIPv2
 Configuring RIPv2 on a
Cisco router
-Requires using the
version 2 command
-RIPv2 ignores RIPv1
updates
 To verify RIPv2 is
configured use the
show ip protocols
command
ITE PC v4.0
Chapter 1 17© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Configuring RIPv2
 Auto-Summary & RIPv2
 RIPv2 will automatically
summarize routes at
major network
boundaries and can
also summarize routes
with a subnet mask that
is smaller than the
classful subnet mask
ITE PC v4.0
Chapter 1 18© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
 Disabling AutoSummary
in RIPv2
 To disable automatic
summarization issue
the no auto-summary
command
Configuring RIPv2
ITE PC v4.0
Chapter 1 19© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Configuring RIPv2
 Verifying RIPv2 Updates
 When using RIPv2 with automatic summarization turned off
Each subnet and mask has its own specific entry, along
with the exit interface and next-hop address to reach that
subnet.
 To verify information being sent by RIPv2 use the
debug ip rip command
ITE PC v4.0
Chapter 1 20© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
VLSM & CIDR
 RIPv2 and VLSM
 Networks using a VLSM IP
addressing scheme
Use classless
routing protocols (i.e.
RIPv2) to
disseminate
network addresses
and their subnet
masks
ITE PC v4.0
Chapter 1 21© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
VLSM & CIDR
 CIDR uses Supernetting
Supernetting is a bunch of contiguous classful
networks that is addressed as a single
network.
ITE PC v4.0
Chapter 1 22© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
VLSM & CIDR
 To verify that
supernets are
being sent and
received use the
following commands
-Show ip route
-Debug ip rip
ITE PC v4.0
Chapter 1 23© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Verifying & Troubleshooting RIPv2
 Basic Troubleshooting steps
-Check the status of all links
-Check cabling
-Check IP address & subnet mask configuration
-Remove any unneeded configuration commands
 Commands used to verify proper operation of RIPv2
–Show ip interfaces brief
–Show ip protocols
–Debug ip rip
–Show ip route
ITE PC v4.0
Chapter 1 24© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Verifying & Troubleshooting RIPv2
 Common RIPv2 Issues
 When trouble shooting RIPv2 examine the following issues:
Version
Check to make sure you are using version 2
Network statements
Network statements may be incorrectly typed
or missing
Automatic summarization
If summarized routes are not needed then disable
automatic summarization
ITE PC v4.0
Chapter 1 25© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Verifying & Troubleshooting RIPv2
 Reasons why it’s good to authenticate routing information
-Prevent the possibility of accepting invalid routing
updates
-Contents of routing updates are encrypted
 Types of routing protocols that can use authentication
-RIPv2
-EIGRP
-OSPF
-IS-IS
-BGP
ITE PC v4.0
Chapter 1 26© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Summary
Routing
Protocol
Distance
Vector
Classless
Routing
Protocol
Uses
Hold-
Down
Timers
Use of
Split
Horizon
or
Split
Horizon
w/
Poison
Reverse
Max
Hop
count
= 15
Auto
Summary
Support
CIDR
Supports
VLSM
Uses
Authen-
tication
RIPv1 Yes No Yes Yes Yes Yes No No No
RIPv2 Yes Yes Yes Yes Yes Yes Yes Yes Yes
ITE PC v4.0
Chapter 1 27© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public