The Routing Information Protocol (RIP) is an Interior Gateway Protocol (IGP). This document discusses both RIP and Triggered RIP. OpenROUTE supports RIP Version 1 (RIPv1), RIP Version 2 (RIPv2), Triggered RIPv1, and Triggered RIPv2. The document includes the following topics:
Interior Gateway Protocols
The Routing Information Protocol (RIP)
Triggered RIP
Displaying RIP Prompts
Configuring RIP
RIP Commands
Interior Gateway Protocols
Routers that use a common routing protocol form an Autonomous System (AS). This common routing protocol is called an Interior Gateway Protocol (IGP). IGPs dynamically detect network reachability and routing information within an AS and use this information to build the IP routing table. IGPs can also import external routing information into the AS.
Most router loads contain one IGP for building the IP routing table and that is RIP. However, many of the OpenROUTE software loads contain both RIP and OSPF. The Bellman-Ford or the distance-vector algorithm is the basis for RIP. Link-state technology or the Shortest-Path First (SPF) algorithm is the basis for the Open Shortest Path First (OSPF) protocol. Routers can run OSPF and RIP simultaneously.
The Routing Information Protocol (RIP)
RIP is a distance-vector protocol that allows routers to exchange information about destinations for computing routes throughout the network. You should use this routing protocol primarily in homogeneous networks of moderate size. In such networks, it may be to your advantage to run RIP rather that OSPF. (RIPv2 and Triggered RIP provide some of the advantages of OSPF without the complexity.)
Destinations may be either networks or a special destination used to convey a default route. RIP, like OSPF, does not alter IP packets and routes them based on destination address only.
Distance-vector algorithms make each router periodically broadcast its routing tables to all its neighbors. Then a router knowing its neighbors' tables can decide which destination neighbor to use for routing a packet.
Limitations
RIP has the following limitations. These limitations apply to both RIPv1 and RIPv2.
The flags described in Table 2 control how the router incorporates information that RIP receives into its routing tables. At the RIP Config> prompt, you use the enable/disable receiving commands to configure RIP receive flags.
The flags described in Table 3 also control how the router incorporates information that RIP receives into its routing tables. Certain flag settings allow RIP routes to override static routing information, but only if the RIP metric is better than the static route's metric. At the RIP Config> prompt, you use the enable/disable override commands to configure RIP override flags.
Triggered RIP
The objective of Triggered RIP is to reduce IP routing traffic to zero traffic over a WAN connection as long as there are no changes to the routing database. It is a modification to RIP, which depends heavily on frequently broadcasting routing information to the router's neighbors. This periodic broadcast of routing information every few seconds can have the following results:
*configConfig>protocol ipTo display the RIP monitoring prompt (RIP>), do the following:
Internet protocol user configurationIP config>ripRIP config>
*monitor+protocol ipIP>ripRIP>
RIP Config>enable rip
RIP config>set originate-rip-default
Always originate default route? [No]:
Originate default if EGP/BGP routes available? [No]: y
From AS number [0]?
To network number [0.0.0.0]?
Originate default if OSPF routes available? [No]:
Cost [1]?
RIPv2 next hop [0.0.0.0]?You need to originate a RIP default route for the other routing protocols to which your network may be connected. This default route directs traffic bound for a non-RIP network to a boundary router that functions as a portal. Originating a single default route means that the boundary router does not have to distribute the other network's routing information to the other nodes on its network.Answering Yes means a default route is always originated (that is, defaults to previous behavior). Answering Yes to the EGP/BGP question originates a default whenever there are EGP or BGP routes in the routing table. Answering Yes to if OSPF routes available causes the RIP default to be advertised when OSPF routes are in the routing table. When the router originates a RIP default, it uses the original default cost number.
RIP config>set send-option trigV1
Interface address [0.0.0.0]?11.2.84.42RIP config>set receive-option V1
Interface address [0.0.0.0]?11.2.84.42You can verify the information you configured with the list protocol command.RIP config>list protocol
Add [C]
Adds routes that accept RIP packets and interfaces that run RIP.
Syntax: add
add accept-rip-route
Network number [0.0.0.0]? 128.185.227.21
add interface
Interface address [0.0.0.0]? 128.185.227.21
clear
All configured interface records will be deleted; RIP will use
the default values for subsequent restarts.
Are you sure you want to delete them (Yes or [No]):
clear
Specify nothing to clear global counters, or 'Interface ip_addr' to clear interface counters, or 'Neighbor ip_addr' to clear neighbor counters.
delete accept-rip-route
Enter the address to be deleted [0.0.0.0]?128.185.227.10
delete interface
Interface address [0.0.0.0]?128.185.227.16
disable interface
Interface address [0.0.0.0]? 128.185.220.45
disable override default
Set for which interface address [0.0.0.0]?128.185.223.67
disable override static-routes
Set for which interface address [0.0.0.0]?128.185.223.67
disable receiving rip
Set for which interface address [0.0.0.0]?128.185.223.67
disable receiving dynamic all
Set for which interface address [0.0.0.0]?128.185.220.64
rip
Turns off RIP.
Example: disable rip sending
Prevents the router's selected interface from advertising all routes or selected routes.
Syntax: disable sending
disable sending default-routes
Set for which interface address [0.0.0.0]?128.185.223.6
Dump [M]
Displays the RIP routing table. Lists a separate entry for each reachable RIP network or subnetwork. If there is a RIP default gateway in use, it appears at the end of the display.
This command is available at the RIP> prompt for convenience. To display more information, enter this command at the IP Config> prompt. See Using IP.
dump
Type Dest net Mask Cost Age Next hop(s)
Sbnt 50.0.0.0 FF000000 1 0 None
Dir* 50.10.1.0 FFFFFF00 1 0 Eth/0
Routing table size: 768 nets (64512 bytes), 2 nets known
enable interface
Interface address [0.0.0.0]?128.185.225.63
enable override default
Set for which interface address [0.0.0.0]?128.185.223.67
enable override static-routes
Set for which interface address [0.0.0.0]?128.185.223.67
enable receiving rip
Set for which interface address [0.0.0.0]?128.185.223.67
enable receiving dynamic nets
Set for which interface address [0.0.0.0]?128.185.227.23
rip
Enables RIP processing on your router.
Example: enable rip sending
Enables sending all routes or specified types of routes. Each separate enable sending command specifies that a certain set of routes should be advertised from a particular interface. The router includes a route in a RIP update only if you have included it by at least one of the enable sending command options.
Syntax: enable sending
enable sending all-routes
Set for which interface address [0.0.0.0]?128.185.66.31
Interface [M]
Displays a summary of the running state of all configured RIP interfaces. Also, displays the configured values and the neighbors that it recognizes on its network, if you specify a particular interface in the command.
Syntax: interface
interface 50.10.1.63
IP-Address Intf State BadPkts BadRtes TrigUpdts Nbrs (V1)
50.10.1.63 Eth/0 On 0 39663 13513 0 (0)
If you enter a specific interface address with the interface command, OpenROUTE displays additional information on the designated interface.
Example:
interface 50.10.1.65
IP-Address Intf State BadPkts BadRtes TrigUpdts Nbrs (V1)
50.10.1.6 Eth/0 On 0 39663 13513 0 (0)Source Address: 50.10.1.65
Authentication Type: None
Default cost: 0
Send option: V1&2
Receive option: V1&2
Per-interface address flags: Send net and subnet routes
Receive No Dynamic host routes
Neighbors: None
list all
RIP: enabled
Intf IP-address Source-address State AuType DefCost Send Recv
0 50.10.1.6 50.10.1.6 On None 0 V1 V1
RIP default origination: disabled
Per-interface address flags:
intf 0 50.10.1.6 Send net, subnet and host routes
Accept RIP updates always for:
128.185.227.22 128.185.227.21
Per-interface address flags displayed are the enabled send flags and the disabled receive flags. protocol
Displays the configured state of RIP.
Example: list protocol
RIP: enabled
Intf IP-address Source-address State AuType DefCost Send Recv
0 50.10.1.65 50.10.1.65 On None 0 V1 V1
RIP default origination: disabled
Per-interface address flags:
intf 0 50.10.1.65 Send net, subnet and host routes
list rip-routes-accept
Accept RIP updates always for:
128.185.227.22 128.185.227.21
neighbor
Neighbor-Addr Phys Vers Age BadPkts BadRtes RxSeq
128.185.223.1 PPP/0 V2 20 0 0 n/a
128.185.112.2 PPP/1 V2 10 0 0 n/a
Ping [M]
Causes your router to send Internet Control Message Protocol (ICMP) Echo Requests to a given destination once per second and then watch for a response. You can use the ping command to isolate trouble in an internetwork environment.
The ping process continues incrementing the ICMP sequence number with each additional packet. OpenROUTE reports matching ICMP Echo responses received with their sequence number and the round-trip time. The process stops when you type a character. At that time, OpenROUTE displays a summary of packet loss, round-trip time, and the number of ICMP unreachable destinations. The round trip usually takes about 20 milliseconds (depending on the router platform).
When a destination has a multicast address, OpenROUTE may display multiple responses for each packet sent, one for each member of the multicast group. Each response contains the source address of the responding system.
Syntax: ping interface-address
Example:ping 128.185.142.11
PING 128.185.142.11: 56 data bytes
64 bytes from 128.185.142.11: icmp_seq=0. time=0. ms
64 bytes from 128.185.142.11: icmp_seq=1. time=0. ms
64 bytes from 128.185.142.11: icmp_seq=2. time=0. ms
64 bytes from 128.185.142.11: icmp_seq=3. time=0. ms
64 bytes from 128.185.142.11: icmp_seq=4. time=0. ms
64 bytes from 128.185.142.11: icmp_seq=5. time=0. ms
----128.185.142.11 PING Statistics----
6 packets transmitted, 6 packets received, 0% packet loss
round-trip (ms) min/avg/max = 0/0/0
Syntax: route ip_destination_address
Example:route 50.10.1.6
Destination: 50.10.1.0
Mask: 255.255.255.0
Route type: Dir
Distance: 1
Age: 0
Next hop(s): 50.10.1.65 (Eth/0)
Tag: 0x00000000
set authentication none
Interface address [0.0.0.0]?
set authentication simple-password
Interface address [0.0.0.0]? 50.10.1.65
Authentication key? john
Enter Auth key again? john
|
None
| No password checks. This is the default. |
|
Simple-password
| Use a cleartext password. Such a password is in alphanumeric or character mode. |
default-metric
Sets the default metric to be used for the default route on this interface. The metric range is 1-15 hops, and 0 (zero) is the default value.
If you set the default metric to 0, OpenROUTE uses the global default metric that you specified by the set-originate-rip-default command.
When you first define an interface, OpenROUTE sets the default metric value for the interface to 0. If you specify the default metric, however, the defined metric takes precedence over the one you configured with the set originate-rip-default command. This applies for both RIPv1 and RIPv2.
Example: set default-metric
Interface address [0.0.0.0]? 50.10.1.65
Default metric (1-15), or 0 to use the global default [0]? 1
set max-retry
Interface address [0.0.0.0]? 50.10.1.65
Maximum number of retries (1-255) [36]? 5
set originate-rip-default
Always originate default route? [No]:Example:
Originate default if EGP/BGP routes available? [No]:
Originate default if OSPF routes available? [No]:
set originate-rip-default
Always originate default route? [No]: yExample:
Cost [3]?
RIPv2 next hop [1.2.3.4]?
set originate-rip-default
Always originate default route? [Yes]: n
Originate default if EGP/BGP routes available? [No]: y
From AS number [0]?
To network number [0.0.0.0]?
Originate default if OSPF routes available? [No]: y
Cost [3]?
RIPv2 next hop [1.2.3.4]?Note: The actual displays in the examples depend on your router's current configuration and your responses to the queries.
set poll-timer
Interface address [0.0.0.0]? 128.181.97.16
Poll Timer [30]?
set receive-option both
All interfaces (Yes or [No]):
Interface address [0.0.0.0]? 126.181.26.2
|
None
| Receive no RIP packets at all. |
|
Both
| Receive both RIPv1 and RIPv2 packets. |
|
V1
| Receive only RIPv1 packets. This is the default. |
|
V2
| Receive only RIP v2 packets. |
reply-timer
For Triggered RIP, sets the number of seconds to wait for a routing response or acknowledgment from the neighbor on a given interface before retransmitting the routing request or response.
The range is 1-255 seconds. The default is 5 seconds.
Example: set reply-timer
Interface address [0.0.0.0]? 50.10.1.6
Reply Timer [5]?
set send-option both
All interfaces (Yes or [No]):
Interface address [0.0.0.0]? 128.185.226.25
source-address
Source addresses are only relevant for unnumbered IP interfaces. OpenROUTE uses a source address as the address for any RIP packet advertised on the designated interface.set source-address
Interface address [0.0.0.0]? 50.10.1.6
Source address [0.0.0.0]? 128.180.22.13
statistics
Originate default route: No (0, 0.0.0.0)
RIP interfaces: 1
Memory allocation failures: 0
I/O buffer allocation failures: 0
Responses sent to neighbors queries: 12
Changes made to the routing database: 10591
Traceroute [M]
Displays the entire path to a destination, hop by hop. For each successive hop, the traceroute command sends out three probes and displays the IP address of the responding system, together with the round-trip time associated with the response. If a particular probe receives no response, OpenROUTE displays an asterisk. Each line in the display relates to the set of three probes, with the left-most number indicating the distance (in router hops) from the router sending the command.
A traceroute is complete when
This command is available at the RIP> prompt for convenience. For more information, enter this command at the IP> prompt. See Using IP.
Syntax: traceroute interface address
Example:traceroute 128.185.124.110
TRACEROUTE 128.185.124.110: 56 data bytes
1 128.185.142.7 16 ms 0 ms 0 ms
2 128.185.123.22 16 ms 0 ms 16 ms
3 * * *
4 * * *
5 128.185.124.110 16 ms ! 0 ms ! 0 ms !