rip permits a maximum of 15 hops to prevent what?

Configuring RIP

This section describes how to configure RIP using the CLI interface.

To brandish RIP configuration information and statistics, encounter Overview of RIP. For more than information on configuring RIP, see Viewing RIP information.

Overview of RIP

Routing Data Protocol (RIP) is an IP route exchange protocol that uses a distance vector (a number representing distance) to measure the cost of a given route. The cost is a altitude vector because the cost oft is equivalent to the number of router hops between the routing switch and the destination network.

An routing switch can receive multiple paths to a destination. The software evaluates the paths, selects the best path, and saves the path in the IP road table equally the route to the destination. Typically, the best path is the path with the fewest hops. A hop is another router through which packets must travel to achieve the destination. If the routing switch receives an RIP update from some other router that contains a path with fewer hops than the path stored in the routing switch'southward road table, the routing switch replaces the older route with the newer ane. The routing switch then includes the new path in the updates information technology sends to other RIP routers, including routing switches.

RIP routers, including routing switches, also can modify a road'south cost, generally by calculation to it, to bias the choice of a route for a given destination. In this instance, the actual number of router hops may be the same, merely the route has an administratively higher cost and is thus less likely to be used than other, lower-price routes. A RIP route can have a maximum cost of xv. Any destination with a higher cost is considered unreachable. Although limiting to larger networks, the depression maximum hop count prevents countless loops in the network.

The switches support the following RIP types:

  • Version i

  • V1 compatible with V2

  • Version 2 (the default)


[NOTE: ]

Notation: If the routing switch receives an ARP request packet that it is unable to deliver to the final destination because of the ARP timeout and no ARP response is received (the routing switch knows of no route to the destination address), the routing switch sends an ICMP Host Unreachable message to the source.


RIP parameters and defaults

The following tables list the RIP parameters, their default values, and where to find configuration data.

RIP global parameters

RIP global parameters lists the global RIP parameters and their default values.

RIP global parameters

Parameter Description Default
RIP state Routing Data Protocol V2-only. Disabled
auto-summary Enable/disable advertisement of summarized routes. Enabled
metric Default metric for imported routes. ane
redistribution RIP tin can redistribute static, and connected routes. (RIP redistributes connected routes by default, when RIP is enabled.) Disabled

RIP interface parameters

RIP interface parameters lists the VLAN interface RIP parameters and their default values.

RIP interface parameters

Parameter Description Default
RIP version The version of the protocol that is supported on the interface.

The version can be one of the following:

  • Version 1 but

  • Version two only

  • Version 1 or version 2

V2-only
metric A numeric cost the routing switch adds to RIP routes learned on the interface. This parameter applies simply to RIP routes. 1
IP address The routes that a routing switch learns or advertises can be controlled. The routing switch learns and advertises all RIP routes on all RIP interfaces
loop prevention The method the routing switch uses to foreclose routing loops caused by advert a route on the same interface equally the one on which the routing switch learned the route:
  • Split horizon — The routing switch does not annunciate a route on the aforementioned interface as the ane on which the routing switch learned the route.

  • Poison reverse — The routing switch assigns a cost of 16 "infinite" or "unreachable") to a route before advertising it on the same interface equally the one on which the routing switch learned the road.

Poison reverse
receive Define the RIP version for incoming packets V2-only
send Define the RIP version for outgoing packets V2-only

Configuring RIP parameters

Apply the following procedures to configure RIP parameters on a system-wide and individual VLAN interface ground.

Enabling RIP

RIP is disabled by default. To enable it, use one of the following methods. When you enable RIP, the default RIP version is RIPv2-only. Yous can change the RIP version on an individual interface basis to RIPv1 or RIPv1-or-v2, if needed.

To enable RIP on a routing switch, enter the post-obit commands:

HP Switch(config)# ip routing                
HP Switch(config)# router rip                
HP Switch(rip)# exit                
HP Switch(config)# write memory                

[NOTE: ]

NOTE: IP routing must be enabled prior to enabling RIP. The first command in the preceding sequence enables IP routing.


Enabling RIP on the routing switch and entering the RIP router context

Syntax:

[no] router rip [[enable] | [disable]] [car-summary]

Executed at the global configuration level to enable RIP on the routing switch and to enter the RIP router context. This enables you lot to proceed with assigning RIP areas and to change RIP global parameter settings as needed. Global IP routing must be enabled earlier the RIP protocol tin can be enabled.

Default: Disabled

enable Enables RIP routing.
disable Disables RIP routing.

The no course of the command deletes all protocol-specific data from the global context and interface context. All protocol parameters are prepare to default values.


[NOTE: ]

Annotation: If you lot disable RIP, the switch retains all the configuration data for the disabled protocol in wink memory. If you subsequently restart RIP, the existing configuration will be applied.

The auto-summary form of the command enables advertisement of the summarized routes. When used with the no form of the command, auto-summary disables the advertising of the summarized routes.


Enter RIP router context

HP Switch(config)# router rip HP Switch(rip)#                

Enable RIP routing

HP Switch(config)# router rip enable HP Switch(rip)#                

Disable RIP routing

HP Switch(config)# router rip disable HP Switch(rip)#                

Delete all protocol-specific information from the global and interface context

HP Switch(config)# no router rip HP Switch(rip)#                

[NOTE: ]

Notation: Deleting all protocol-specific information from the global and interface context sets all protocol parameters to default values.



[NOTE: ]

Note: IP routing must be enabled prior to enabling RIP. The first control in the preceding sequence enables IP routing.


Enabling IP RIP on a VLAN

To enable RIP on all IP addresses in a VLAN, use ip rip in the VLAN context. When the command is entered without specifying whatever IP address, it is enabled in all configured IP addresses of the VLAN.

To enable RIP on a specific IP accost in a VLAN, use ip rip [< ip-addr >|all] in the VLAN context and enter a specific IP address. If you desire RIP enabled on all IP addresses, you tin specify all in the control instead of a specific IP address.

Changing the RIP type on a VLAN interface

When yous enable RIP on a VLAN interface, RIPv2-only is enabled by default. Y'all tin can modify the RIP type to one of the post-obit on an individual VLAN interface basis:

  • Version one but

  • Version two only (the default)

  • Version 1 - or - version two

To change the RIP type supported on a VLAN interface, enter commands such as the following:

HP Switch(config)# vlan 1                
HP Switch(vlan-ane)# ip rip v1-only                
HP Switch(vlan-1)# exit                
HP Switch(config)# write retention                
Syntax:

[no] ip rip <v1-only | v1-or-v2 | v2-simply>

Irresolute the cost of routes learned on a VLAN interface

By default, the switch interface increases the cost of an RIP route that is learned on the interface. The switch increases the cost by adding one to the road's metric before storing the road.

You tin can change the amount that an individual VLAN interface adds to the metric of RIP routes learned on the interface.


[NOTE: ]

NOTE: RIP considers a route with a metric of 16 to exist unreachable. Utilise this metric only if you do not desire the road to be used. In fact, yous tin prevent the switch from using a specific interface for routes learned though that interface by setting its metric to xvi.


To increase the price a VLAN interface adds to RIP routes learned on that interface, enter commands such every bit the following:

HP Switch(config)# vlan ane                
HP Switch(vlan-1)# ip rip metric 5                

These commands configure vlan-one to add five to the cost of each road learned on the interface.

Syntax:

Configuring RIP redistribution

You can configure the routing switch to redistribute connected, static, and OSPF routes into RIP. When you redistribute a route into RIP, the routing switch can use RIP to advertise the road to its RIP neighbors.

To configure redistribution, perform the post-obit tasks:

  1. Configure redistribution filters to allow or deny redistribution for a route based on the destination network address or interface. (optional)

  2. Enable redistribution.

Defining RIP redistribution filters

Route redistribution imports and translates different protocol routes into a specified protocol type. On the switches covered in this guide, redistribution is supported for static and directly connected routes. Redistribution of whatever other routing protocol into RIP is not currently supported. When yous configure redistribution for RIP, y'all can specify that static or connected routes are imported into RIP routes.

Configuring for redistribution

To configure for redistribution, ascertain the redistribution tables with "restrict" redistribution filters. In the CLI, utilise the restrict control for RIP at the RIP router level.


[NOTE: ]

Annotation: Exercise not enable redistribution until y'all have configured the redistribution filters. Otherwise, the network might become overloaded with routes that y'all did not intend to redistribute.

Instance:

To configure the switch to filter out redistribution of static or connected routes on network x.0.0.0, enter the following commands:

HP Switch(config)# router rip                            
HP Switch(rip)# restrict 10.0.0.0 255.0.0.0                            
HP Switch(rip)# write memory                            

The default configuration permits redistribution for all default connected routes only.


Syntax:

restrict < ip-addr > < ip-mask > | < ip-addr/ < prefix length >

This command prevents any routes with a destination address that is included in the range specified by the address/mask pair from existence redistributed by RIP.

Modifying default metric for redistribution

The default metric is a global parameter that specifies the cost applied to all RIP routes past default. The default value is 1. You lot tin can assign a cost from 1 to xv.

Example:

To assign a default metric of four to all routes imported into RIP, enter the following commands:

HP Switch(config)# router rip                
HP Switch(rip)# default-metric iv                
Syntax:

default-metric < value >

The < value > tin can be from ane to 15. The default is 1.

Enabling RIP road redistribution

The basic class of the redistribute command redistributes all routes of the selected type. For effectively control over road pick and modification of route properties, you tin can specify the route-map parameter and the name of a route map.


[NOTE: ]

NOTE: Practise not enable redistribution until you lot take configured the redistribution filters. Otherwise, the network might go overloaded with routes that you did non intend to redistribute.


Syntax:

[no] router rip redistribute <connected | static> [route-map < name >]

Enables redistribution of the specified route type to the RIP domain.

static

Redistribute from manually configured routes.

connected

Redistribute from locally connected networks.

route-map <proper name>

Optionally specify the name of a route-map to use during redistribution.

The no form of the control disables redistribution for the specified route type.

Instance:

To enable redistribution of all connected, static, and OSPF routes into RIP, enter the following commands.

HP Switch(config)# router rip                
HP Switch(rip)# redistribute continued                
HP Switch(rip)# redistribute static                
HP Switch(rip)# write memory                

Changing the route loop prevention method

Syntax:

[no] ip rip poison-contrary

Entering the command without the no option will re-enable Poison reverse.

RIP tin can utilize the following methods to forbid routing loops:

  • Dissever horizon - the routing switch does not advertise a road on the same interface as the one on which the routing switch learned the route.

  • Toxicant contrary - the routing switch assigns a price of sixteen ("infinity" or "unreachable") to a route before advertisement it on the same interface every bit the one on which the routing switch learned the road. This is the default.

These loop prevention methods are configurable on an individual VLAN interface basis.


[NOTE: ]

Notation: These methods are in addition to RIP'due south maximum valid road price of xv.


Poison contrary is enabled by default. Disabling Poison reverse causes the routing switch to revert to Split horizon. (Toxicant reverse is an extension of Split horizon.) To disable Poison reverse on an interface, and thereby enable Split horizon, enter the following:

HP Switch(config)# vlan 1              
HP Switch(vlan-one)# no ip rip poison-contrary              

Viewing RIP information

All RIP configuration and status information is shown by the CLI command prove ip rip and options off that command.

Viewing general RIP data

Syntax:

To brandish general RIP information, enter show ip rip at whatsoever context level. The resulting display volition announced similar to the following:

General RIP data listing

HP Switch(config)# show ip rip  RIP global parameters    RIP protocol   : enabled   Auto-summary   : enabled    Default Metric : ane   Distance       : 120   Route changes  : 0   Queries        : 0  RIP interface information    IP Accost  Status   Send mode Recv mode  Metric  Auth   ----------- -------- --------- ---------- ------- ----   100.1.0.1   enabled  V2-but   V2-just    five       none   100.2.0.1   enabled  V2-but   V2-only    five       none   100.3.0.i   enabled  V2-only   V2-just    5       none   100.4.0.1   enabled  V2-only   V2-only    5       none   100.10.0.ane  enabled  V2-just   V2-only    v       none   100.11.0.1  enabled  V2-but   V2-but    5       none  RIP peer information    IP Address      Bad routes  Last update timeticks   --------------- ----------- ---------------------              

The display is a summary of global RIP data, information about interfaces with RIP enabled, and information about RIP peers. The following fields are displayed:

RIP protocol

Status of the RIP protocol on the router. RIP must exist enabled here and on the VLAN interface for RIP to be agile.

The default is disabled.

Auto-summary

Status of auto-summary for all interfaces running RIP. If car-summary is enabled, subnets will be summarized to a class network when advertizing exterior of the given network.

Default metric

Sets the default metric for imported routes. This is the metric that volition be advertised with the imported road to other RIP peers. A RIP metric is a measurement used to determine the "best" path to network: i is the best, 15 is the worst, sixteen is unreachable.

Route changes

The number of times RIP has modified the routing switch's routing tabular array.

Queries

The number of RIP queries that have been received by the routing switch.

RIP interface information

RIP information on the VLAN interfaces on which RIP is enabled:

IP address

IP address of the VLAN interface running RIP.

Status

Status of RIP on the VLAN interface.

Send mode

Format of the RIP updates: RIP 1, RIP two, or RIP two version 1 uniform.

Recv mode

The switch tin can process RIP 1, RIP 2, or RIP 2 version 1 compatible update messages.

Metric

Path "cost", a measurement used to determine the "best" RIP route path: one is the best, 15 is the worst, sixteen is unreachable.

Auth

RIP messages tin exist required to include an authentication key if enabled on the interface.

RIP peer information

RIP peers are neighboring routers from which the routing switch has received RIP updates:

IP address

IP accost of the RIP neighbour.

Bad routes

Number of road entries which were not processed for any reason.

Final update timeticks

Number of seconds that have passed since we received an update from this neighbor.

Viewing RIP interface information

To display RIP interface information, enter the show ip rip interface control at any context level.

Syntax:

show ip rip interface [ ip-addr | vlan < vlan-id > ]

The resulting display will appear similar to the following:

Output for the show IP RIP interface control

HP Switch(config)# show ip rip interface   RIP interface data    IP Accost  Status   Send style  Recv way  Metric  Auth   ----------- -------- ---------- ---------- ------- ----   100.i.0.i   enabled  V2-simply    V2-only    i       none   100.2.0.i   enabled  V2-only    V2-only    1       none   100.iii.0.1   enabled  V2-only    V2-only    1       none   100.four.0.1   enabled  V2-only    V2-only    ane       none                  

Y'all can also brandish the information for a single RIP VLAN interface, past specifying the VLAN ID for the interface, or past specifying the IP address for the interface.

To prove the RIP interface data for VLAN m, use the show ip rip interface vlan < vid > command.

RIP interface output by VLAN

HP Switch# testify ip rip interface vlan 4   RIP configuration and statistics for VLAN four   RIP interface information for 100.4.0.1    IP Address : 100.four.0.1   Status     : enabled    Send Style  : V2-only    Recv mode  : V2-only    Metric : 1   Auth : none    Bad packets received : 0   Bad routes received  : 0   Sent updates : 0              

For definitions of the fields in RIP interface output past VLAN, see Viewing general RIP data.

The RIP interface data also includes the following fields:

Bad packets received Number of packets that were received on this interface and were non processed for any reason.
Bad routes received Number of route entries that were received on this interface and were not candy for whatsoever reason.
Sent updates Number of RIP routing updates that have been sent on this interface.

To testify the RIP interface information for the interface with IP address 100.2.0.1, enter the testify ip rip interface command:

The show IP rip interface output past IP address

HP Switch# bear witness ip rip interface 100.two.0.1   RIP interface information for 100.2.0.1    IP Address : 100.2.0.ane   Status    : enabled    Send Way : V2-merely    Recv mode : V2-only    Metric : i   Auth : none    Bad packets received : 0   Bad routes received  : 0   Sent updates : 0              

Viewing RIP peer data

To brandish RIP peer information, enter the show ip rip peer command at any context level.

The resulting display will appear similar to the following:

Output for the evidence IP rip peer control

HP Switch# show ip rip peer  RIP peer information   IP Address      Bad routes  Last update timeticks  --------------- ----------- ---------------------  100.1.0.100     0           1  100.2.0.100     0           0  100.3.0.100     0           2  100.10.0.100    0           ane              

This display lists all neighboring routers from which the routing switch has received RIP updates. The following fields are displayed:

IP accost IP address of the RIP peer neighbour.
Bad routes The number of route entries that were not candy for whatever reason.
Last update timeticks How many seconds have passed since the routing switch received an update from this peer neighbor.

To bear witness the RIP peer information for a specific peer with IP accost 100.i.0.100, enter show ip rip peer 100.1.0.100.

Output for the show IP rip peer <ip-addr> command

HP Switch# show ip rip peer 100.0.one.100  RIP peer information for 100.0.ane.100    IP Address : 100.i.0.100   Bad routes : 0   Concluding update timeticks : ii              

This brandish lists information in the fields described above (IP address, Bad routes, Last update timeticks.)

Viewing RIP redistribution information

To display RIP redistribution information, enter the evidence ip rip redistribute command at any context level:

Output for the show IP rip redistribute command

HP Switch# show ip rip redistribute  RIP redistributing   Route type Condition  ---------- ------  connected  enabled  static     disabled              

RIP automatically redistributes connected routes that are configured on interfaces that are running RIP and all routes that are learned via RIP. The router rip redistribute command, described in Configuring for redistribution, configures the routing switch to cause RIP to advertise connected routes that are not running RIP or static routes. The display shows whether RIP redistribution is enabled or disabled for connected or static routes.

Viewing RIP redistribution filter (restrict) data

To display RIP restrict filter data, enter the bear witness ip rip restrict command at whatever context level:

Output for the show IP rip restrict control

HP Switch# show ip rip restrict  RIP restrict listing   IP Address      Mask  --------------- ------------              

The display shows if any routes identified past the IP Address and Mask fields are being restricted from redistribution. The restrict filters are configured by the router rip restrict command (encounter Configuring for redistribution).

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Source: https://techhub.hpe.com/eginfolib/networking/docs/switches/WB/16-01/5200-0143_wb_2920_mrg/content/ch03s07.html

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