The Advanced RIP Features contained in this configuration module cover the implementation of RFC 1724, which allows you to monitor RIPv2 using SNMP, and the information about configuring the cable modem HFC RIP Relay feature.
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see
Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
Cable technology has been adapting to the deployment of fiber since 1994, leading to hybrid solutions known as hybrid fiber-coaxial (HFC). HFC networks contain both optical-fiber and coaxial cable lines. Optical fiber is deployed from the cable headend to cable operator subscribers with up to 2000 subscribers. Coaxial cable is deployed from the optical-fiber feeders to each subscriber. Hybrid networks provide the bandwidth and reliability of optical fiber at a lower cost than a pure fiber network.
HFC RIP Relay
The cable modem HFC RIP Relay feature allows the delivery of Routing Information Protocol (RIP) messages from a Cisco IOS router containing an integrated cable modem to the hybrid fiber-coaxial (HFC) cable modem termination system (CMTS) when they are on different subnets. The integrated cable modem may be physically integrated into the router or via a cable modem high-speed WAN interface card (HWIC). In previous Cisco IOS releases, RIP messages were rejected by the CMTS because the interface on the Cisco IOS router was in a different subnet from the CMTS. The solution involves trapping and handling RIP messages by the cable modem and ensuring that the RIP messages are forwarded to the router. The cable modem HFC RIP Relay feature enhances the scalability, security, and certification requirements of cable operators who require RIP to provision and manage customer cable modems.
In the provisioning systems used by some cable operators, when a Cisco IOS router containing an integrated cable modem is connected to a CMTS, RIP messages are rejected because the IP address derived from a DHCP request for the router is from a different pool of IP addresses than for the cable modems. The RIP messages are rejected by the CMTS because the interface on the Cisco IOS router is in a different subnet from the CMTS. Without requiring additional configuration on the CMTS, the HFC RIP Relay feature enables the cable modem to bridge the RIP messages between the Cisco IOS router and the CMTS.
The cable modem HFC RIP Relay feature is implemented in Cisco IOS Release 12.4(15)XY, 12.4(20)T, and later releases. The feature requires the cable modem firmware version filename of C21031014bFU07192007.CDF in the United States or the cable modem firmware version filename of C21041014bFU07192007.CDF in Europe and Japan, and the feature is turned off by default. To enable HFC RIP relay, use the new service-moduleipriprelay command-line interface (CLI) command.
Support is added for configuring a static IP address on the cable modem interface. Configuring a static IP address for the Cisco IOS router with an integrated cable modem is also supported in Cisco IOS Release 12.4(15)XY, 12.4(20)T, and later releases using the ipaddress command.
Benefits of the RIPv2 MIB
The RFC 1724 RIPv2 MIB extensions allow network managers to monitor the RIPv2 routing protocol using SNMP through the addition of new global counters and table objects that previously were not supported by the RFC 1389 RIPv2 MIB. The new global counters and table objects are intended to facilitate quickly changing routes or failing neighbors.
RIPv2 MIB
This document describes the Cisco IOS implementation of RFC 1724,
RIP Version 2 MIB Extensions . RIPv2 using Simple Network Management Protocol (SNMP).
This section describes the MIB objects that are provided by RFC 1724 definitions. The RIPv2 MIB consists of the following managed objects:
Global counters--Used to keep track of changing routes or neighbor changes.
Interface status table--Defines objects that are used to keep track of statistics specific to interfaces.
Interface configuration table--Defines objects that are used to keep track of interface configuration statistics.
Peer table--Defined to monitor neighbor relationships. This object is not implemented in Cisco IOS software.
The tables below show the objects that are provided by RFC 1724 RIPv2 MIB definitions. The objects are listed in the order in which they appear within the RFC 1724 RIPv2 MIB, per the tables that describe them. The statistics for all of the objects in the global counters can be obtained by querying the rip2Globals object identifier (OID) using
snmpwalk or a similar SNMP toolset command on your Network Management Station (NMS).
The table below shows the RFC 1724 RIPv2 MIB global counter objects.
Table 1 RFC 1724 RIPv2 MIB Global Counters Objects
Global Counter
Object
Description
rip2Globals
rip2GlobalRouteChanges
Number of route changes made to the IP route database by RIP. The number is incremented when a route is modified.
rip2GlobalQueries
Number of responses sent to RIP queries from other systems. The number is incremented when RIP responds to a query from another system.
The objects in the RFC 1724 RIPv2 MIB interface table track information on a per-interface basis. All objects in the RFC 1724 RIPv2 MIB interface table, except for the rip2IfStatAddress object, represent newly tracked data within RIP. There are no equivalent
show commands for these objects. All objects in the RIPv2 MIB interface table are implemented read-only.
The table below shows the RFC 1724 RIPv2 MIB interface table objects. The statistics for all objects in the interface table can be obtained by querying the sequence name Rip2IfStatEntry using
snmpwalk or a similar SNMP toolset command on your NMS.
The IP address of this system on the indicated subnet. For unnumbered interfaces, the value of 0.0.0.N, where the least significant 24 bits (N) are the ifIndex for the IP interface in network byte order.
rip2IfStatRcvBadPackets
The number of RIP response packets received by the RIP process that were subsequently discarded for any reason. For example, a version 0 packet or an unknown command type.
rip2IfStatRcvBadRoutes
The number of routes, in valid RIP packets, that were ignored for any reason. This is incremented when:
The address family identifier does not equal AF_INET.
A RIP v2 update is received and the address is not a RIP multicast address (244.0.0.0) or RIP broadcast address (255.255.255.255).
A RIP v2 update is received and the address is a martian address.
rip2IfStatSentUpdates
The number of triggered RIP updates actually sent on this interface. This explicitly does not include full updates sent containing new information.
rip2IfStatStatus
This value is always set to 1.
The objects in the RFC 1724 RIPv2 MIB interface configuration table track information on a per- interface basis. Except for the Rip2IfConfAuthType object, the data for the objects in the RFC 1724 RIPv2 MIB interface configuration table can also be gathered using the
showipprotocol commands. All objects in the RIPv2 MIB interface table are implemented read-only.
The table below shows the RIPv2 MIB interface configuration table objects. The statistics for all objects in the configuration table can be obtained by querying the sequence name rip2IfConfEntry using
snmpwalk or a similar SNMP toolset command on your NMS.
The IP address of this system on the indicated subnet. For unnumbered interfaces, the value 0.0.0.N, where the least significant 24 bits (N) are the ifIndex for the IP interface in network byte order.
rip2IfConfDomain
This value is always equal to "".
rip2IfConfAuthType
The type of authentication used on this interface.
rip2IfConfAuthKey
The value to be used as the authentication key whenever the corresponding instance of rip2IfConfAuthType has a value other than no authentication.
rip2IfConfSend
The version of RIP updates that are sent on this interface.
rip2IfConfReceive
The version of RIP updates that are accepted on this interface.
rip2IfConfDefaultMetric
This variable indicates the metric that is used for the default route entry in RIP updates originated on this interface.
rip2IfConfStatus
This value is always set to 1.
rip2IfConfSrcAddress
The IP address that this system will use as a source address on this interface. If it is a numbered interface, this must be the same value as rip2IfConfAddress. On unnumbered interfaces, it must be the value of rip2IfConfAddress for some interface on the system.
SNMP Community Strings
Routers can have multiple read-only SNMP community strings. When you configure an SNMP read-only community string for the snmp-server command on the router, an existing SNMP snmp-server read-only community string is not overwritten. For example, if you enter the snmp-servercommunitystring1ro and snmp-servercommunitystring2ro commands on the router, the router will have two valid read-only community strings--string1 and string2. If this is not the behavior that you desire, use the nosnmp-servercommunitystringro command to remove an existing SNMP read-only community string.
Timesaver
If you already have an SNMP read-only community string configured on your router you do not need to perform this task. After you load Cisco IOS Release 12.4(6)T or a later release on your router, you can use SNMP commands on your NMS to query the RFC 1724 RIPv2 MIB on your router
The HFC RIP Relay feature requires an Integrated Services Router (ISR) with an integrated cable modem and Cisco IOS Release 12.4(15)XY, 12.4(20)T, or later release and one of the following:
Cable modem firmware version filename of C21031014bFU07192007.CDF in the United States
Cable modem firmware version filename of C21041014bFU07192007.CDF in Europe and Japan
ISR cable products include the Cisco 815, Cisco 1805, and the cable modem HWIC in the Cisco 1800, 2800, and 3800 series routers.
Restrictions
The HFC RIP Relay feature does not support multiple cable modem HWICs in a single router.
Enabling HFC RIP Relay
Perform this task to enable RIP relay on an integrated cable modem. In this task, a static IP address is configured for the cable modem interface and RIP relay is enabled on the interface. Validation of the source IP address of incoming RIP routing updates is disabled to allow RIP updates from unknown sources. RIP is defined as the routing protocol to be used on all interfaces that are connected to networks 10.0.0.0 and 172.18.0.0.
SUMMARY STEPS
1.enable
2.configureterminal
3.interfacetypenumber
4.ipaddressip-addressmask[secondary]
5.service-moduleipriprelay
6.exit
7.routerrip
8.version{1 | 2}
9.novalidate-update-source
10.networkip-address
11.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interfacetypenumber
Example:
Router(config)# interface cable-modem 0/3/0
Configures an interface type and enters interface configuration mode.
In this example, cable-modem interface 0/3/0 is configured.
Step 4
ipaddressip-addressmask[secondary]
Example:
Router(config-if)# ip address 10.5.5.5 255.255.255.0
Sets a primary or secondary IP address for an interface.
In this example, the static IP address of 10.5.5.5 is configured under the cable-modem interface.
Step 5
service-moduleipriprelay
Example:
Router(config-if)# service-module ip rip relay
Enables RIP relay in the ISR cable-modem driver.
Step 6
exit
Example:
Router(config-if)# exit
Exits interface configuration mode and returns to global configuration mode.
Step 7
routerrip
Example:
Router(config)# router rip
Enters router configuration mode for the specified routing process.
In this example, a RIP routing process is configured.
Step 8
version{1 | 2}
Example:
Router(config-router)# version 2
Specifies a RIP version used globally by the router.
In this example, the software sends and receives RIP version 2 packets.
Step 9
novalidate-update-source
Example:
Router(config-router)# no validate-update-source
Disables the validation of the source IP address of incoming RIP routing updates.
When the validation check is enabled, the software ensures that the source IP address of incoming routing updates is on the same IP network as one of the addresses defined for the receiving interface.
In this example, the router is configured not to perform validation checks on the source IP address of incoming RIP updates.
Step 10
networkip-address
Example:
Router(config-router)# network 10.0.0.0
Specifies a list of networks for the RIP routing process.
In this example, RIP is defined as the routing protocol to be used on all interfaces connected to network 10.0.0.0.
Step 11
end
Example:
Router(config-router)# end
Exits router configuration mode and returns to privileged EXEC mode.
Enabling HFC RIP Relay for a Single Subnet and Disabling Split-Horizon
Perform this task to enable RIP relay on an ISR cable modem. In this task, a static IP address is configured for the cable-modem interface and RIP relay is enabled on the interface. Split-horizon is disabled, and RIP is defined as the routing protocol to be used on all interfaces connected to network 10.0.0.0.
SUMMARY STEPS
1.enable
2.configureterminal
3.interfacetypenumber
4.ipaddressip-addressmask[secondary]
5.service-moduleipriprelay
6.noipsplit-horizon
7.exit
8.routerrip
9.version{1 | 2}
10.novalidate-update-source
11.networkip-address
12.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interfacetypenumber
Example:
Router(config)# interface cable-modem 0/3/0
Configures an interface type and enters interface configuration mode.
In this example, cable-modem interface 0/3/0 is configured.
Step 4
ipaddressip-addressmask[secondary]
Example:
Router(config-if)# ip address 10.5.5.5 255.255.255.0
Sets a primary or secondary IP address for an interface.
In this example, a static IP address of 10.5.5.5 is configured under the cable-modem interface.
Step 5
service-moduleipriprelay
Example:
Router(config-if)# service-module ip rip relay
Enables RIP relay in the ISR cable-modem driver.
Step 6
noipsplit-horizon
Example:
Router(config-if)# no ip split-horizon
Disables split horizon, allowing routing updates to be sent from the interface over which the route was learned.
Step 7
exit
Example:
Router(config-if)# exit
Exits interface configuration mode and returns to global configuration mode.
Step 8
routerrip
Example:
Router(config)# router rip
Enters router configuration mode for the specified routing process.
In this example, a RIP routing process is configured.
Step 9
version{1 | 2}
Example:
Router(config-router)# version 2
Specifies a RIP version used globally by the router.
In this example, the software sends and receives RIP version 2 packets.
Step 10
novalidate-update-source
Example:
Router(config-router)# no validate-update-source
Disables the validation of the source IP address of incoming RIP routing updates.
When the validation check is enabled, the software ensures that the source IP address of incoming routing updates is on the same IP network as one of the addresses defined for the receiving interface.
In this example, the router is configured not to perform validation checks on the source IP address of incoming RIP updates.
Step 11
networkip-address
Example:
Router(config-router)# network 10.0.0.0
Specifies a list of networks for the RIP routing process.
In this example, RIP is defined as the routing protocol to be used on all interfaces connected to network 10.0.0.0.
Step 12
end
Example:
Router(config-router)# end
Exits router configuration mode and returns to privileged EXEC mode.
Verifying the Configuration of HFC RIP Relay
Use the following steps to verify the local configuration of HFC RIP relay on a router.
SUMMARY STEPS
1.enable
2.showrunning-config[options]
DETAILED STEPS
Step 1
enable
Enables privileged EXEC mode. Enter your password if prompted.
Example:
Router> enable
Step 2
showrunning-config[options]
Displays the running configuration on the local router. The output will display the configuration of the service-moduleipriprelay command in the cable-modem interface section and of the RIP commands under the RIP protocol section.
Example:
Router# show running-config
.
.
.
interface Cable-Modem0/3/0
ip address 172.20.0.2 255.255.255.0
service-module ip rip relay
no ip split-horizon
.
.
.
router rip
version 2
no validate-update-source
network 10.0.0.0
network 172.18.0.0
.
.
.
Enabling RIPv2 Monitoring with SNMP Using the RIPv2 RFC 1724 MIB Extensions
Your SNMP NMS must have the RFC 1724 RIPv2 MIB installed.
Your SNMP NMS must have the following MIBs installed because RFC 1724 imports data types and object identifiers (OIDs) from them:
SNMPv2-SMI
SNMPv2-TC
SNMPv2-CONF
RFC1213-MIB
Restrictions
This implementation of the RIPv2 MIB does not track any data associated with a RIP Virtual Routing and Forwarding (VRF) instance. Only interfaces that are assigned IP addresses in the IP address space configured by the network command in RIP router configuration mode are tracked. Global data is tracked only for changes to the main routing table.
Enabling SNMP Read-Only Access on the Router
There are no router configuration tasks required for the RIPv2: RFC 1724 MIB Extensions feature itself. SNMP read-only access to the objects in the RFC 1724 RIPv2 MIB is enabled when you configure the SNMP server read-only community string on the router.
Note
When you configure an SNMP server read-only community string on the router, you are granting SNMP read-only access to the objects that support read-only access in all MIBs that are available in the version of Cisco IOS software that is running on the router.
Perform this task to configure the SNMP server read-only community string on the router to enable SNMP read-only access to MIB objects (including the RFC 1724 RIPv2 MIB extensions) on the router.
SUMMARY STEPS
1.enable
2.configureterminal
3.snmp-servercommunitystring1ro
4.end
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
snmp-servercommunitystring1ro
Example:
Router(config)# snmp-server community T8vCx3 ro
Enables SNMP read-only access to the objects in the MIBs that are included in the version of Cisco IOS software that is running on the router.
Note
For security purposes, do not use the standard default value of public for your read-only community string. Use a combination of uppercase and lowercase letters and numbers for the password.
Step 4
end
Example:
Router(config)# end
Ends your configuration session and returns to privileged EXEC mode.
Verifying the Status of the RIPv2 RFC 1724 MIB Extensions on the Router and Your Network Management Station
Perform this optional task on your NMS to verify the status of the RFC 1724 RIPv2 MIB extensions on the router and on your NMS.
This task uses the NET-SNMP toolset that is available in the public domain. The step that is documented uses a terminal session on an NMS that is running Linux. Substitute the SNMP command from the SNMP toolset on your NMS as appropriate when you perform this task.
Use the snmpwalk command for the rip2Globals object in the RFC 1724 RIPv2 MIB to display the data for the objects associated with this object. This step verifies that the NMS is configured to send queries for objects in the RFC 1724 RIPv2 MIB and that the router is configured to respond to the queries.
The following example enables RIP relay on an ISR cable modem. A static IP address is configured for the cable-modem interface, and RIP relay is enabled on the interface. Validation of the source IP address of incoming RIP routing updates is disabled to allow RIP updates from unknown sources. RIP is defined as the routing protocol to be used on all interfaces connected to networks 10.0.0.0 and 172.18.0.0.
interface Cable-Modem0/3/0
ip address 10.5.5.5 255.255.255.0
service-module ip rip relay
exit
router rip
version 2
no validate-update-source
network 10.0.0.0
network 172.18.0.0
Enabling HFC RIP Relay for a Single Subnet and Disabling Split-Horizon Example
The following example enables RIP relay on an ISR cable modem. A static IP address is configured for the cable-modem interface, and RIP relay is enabled on the interface. Validation of the source IP address of incoming RIP routing updates is disabled to allow RIP updates from unknown sources, and split-horizon is disabled. RIP is defined as the routing protocol to be used on all interfaces connected to network 172.20.0.0.
interface Cable-Modem0/3/0
ip address 172.20.0.2 255.255.255.0
service-module ip rip relay
no ip split-horizon
exit
router rip
version 2
no validate-update-source
network 172.20.0.0
Configuration Examples for RIPv2 Monitoring with SNMP Using the RIPv2 RFC1724 MIB Extensions
The following example shows how to send an SNMP query to obtain data for the rip2IfStatStatus object for all the interfaces in the RIP interface status table using the snmpwalk command.
The following example shows how to send an SNMP query to obtain data for the rip2IfStatStatus object for a specific interface IP address in the RIP interface status table using the snmpget command.
Querying the RIP Interface Configuration Table Objects Example
The following example shows how to send an SNMP query to obtain data for all objects in the RIP interface configuration table using the snmpwalk command.
The following example shows how to send an SNMP query to obtain data for the rip2IfConfAddress object for all interfaces in the RIP interface configuration table using the snmpwalk command.
No new or modified standards are supported. and support for existing standards has not been modified.
--
MIBs
MIB
MIBs Link
RIPv2 MIB
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
http://www.cisco.com/go/mibs
RFCs
RFC
Title
RFC 1724
RIP Version 2 MIB Extensions
RFC 2082
RIP-2 MD5 Authentication
RFC 2453
RIP Version 2
Technical Assistance
Description
Link
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Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.
http://www.cisco.com/techsupport
Feature Information for Advanced RIP Features
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 4 Feature Information for Advanced RIP Features
Feature Name
Releases
Feature Information
HFC RIP Relay
12.4(15)XY 12.4(20)T 15.0(1)M 12.2(33)SRE
The HFC RIP Relay feature allows the delivery of Routing Information Protocol (RIP) messages from a Cisco IOS router containing a cable HWIC to the HFC CMTS when they are on different subnets. Configuring a static IP address is now also supported on a cable modem interface.
The following command was introduced by this feature:
service-moduleipriprelay.
RIPv2: RFC 1724 MIB Extension
12.4(6)T 15.0(1)M 12.2(33)SRE
This feature introduces the Cisco IOS implementation of RFC 1724,
RIP Version 2 MIB Extensions . RFC 1724 defines MIB objects that allow the management and limited control of RIPv2 using SNMP.
Glossary
OID--object identifier. A managed object within the object tree.
SNMP--Simple Network Management Protocol. Aprotocol used to monitor and manage networking devices.
snmpget--An SNMP command to query statistics from a specific OID in the MIB.