Contents

Configuring RIPng· 1

About RIPng· 1

RIPng routing metrics· 1

RIPng route entries· 1

RIPng packets and advertisement 1

Protocols and standards· 1

Restrictions: Hardware compatibility with RIPng· 2

RIPng tasks at a glance· 2

Configuring basic RIPng· 2

Configuring RIPng route control 3

Configuring an additional routing metric· 3

Configuring RIPng route summarization· 3

Advertising a default route· 4

Configuring received/redistributed route filtering· 4

Setting a preference for RIPng· 5

Configuring RIPng route redistribution· 5

Tuning and optimizing the RIPng network· 5

Setting RIPng timers· 5

Configuring split horizon and poison reverse· 6

Setting the maximum number of ECMP routes· 6

Configuring the RIPng packet sending rate· 7

Setting the interval for sending triggered updates· 7

Configuring RIPng GR· 8

Enhancing RIPng security· 8

Configuring zero field check for RIPng packets· 8

Applying an IPsec profile· 9

Verifying and maintaining RIPng· 9

Verifying RIPng configuration and running status· 9

Clearing statistics for a RIPng process· 10

Resetting a RIPng process· 10

 

Configuring RIPng

The term router in this chapter refers to a routing-capable device.

About RIPng

RIP next generation (RIPng), as an extension of RIP-2 for support of IPv6, is a distance vector routing protocol. It employs UDP to exchange route information through port 521. Most RIP concepts are applicable to RIPng.

RIPng routing metrics

RIPng uses a hop count to measure the distance to a destination. The hop count is the metric or cost. The hop count from a router to a directly connected network is 0. The hop count between two directly connected routers is 1. When the hop count is greater than or equal to 16, the destination network or host is unreachable.

RIPng route entries

RIPng stores route entries in a database. Each route entry contains the following elements:

·     Destination address—IPv6 address of a destination host or a network.

·     Next hop address—IPv6 address of the next hop.

·     Egress interface—Egress interface of the route.

·     Metric—Cost from the local router to the destination.

·     Route time—Time elapsed since the most recent update. The time is reset to 0 every time the route entry is updated.

·     Route tag—Used to identify external routes.

RIPng packets and advertisement

RIPng multicasts request and response packets to exchange routing information. It uses FF02::9 as the destination address and link-local address FE80::/10 as the source address. RIPng exchanges routing information as follows:

1.     When RIPng starts or needs to update some route entries, it sends a multicast request packet to neighbors.

2.     When a RIPng neighbor receives the request packet, it sends back a response packet that contains the local routing table. RIPng can also advertise route updates in response packets periodically or advertise a triggered update caused by a route change.

3.     After RIPng receives the response, it checks the validity of the response before adding routes to its routing table, including the following details:

¡     Whether the source IPv6 address is the link-local address.

¡     Whether the port number is correct.

4.     A response packet that fails the check is discarded.

Protocols and standards

·     RFC 2080, RIPng for IPv6

·     RFC 2081, RIPng Protocol Applicability Statement

Restrictions: Hardware compatibility with RIPng

Series	Models	Product codes	RIPng compatibility
WX3500X series	WX3510X WX3520X WX3540X	EWP-WX3510X EWP-WX3520X EWP-WX3540X	No
WCG380 series	WCG382	EWP-WCG382	Yes

 

Series	Models	Product codes	RIPng compatibility
WX3800X series	WX3820X WX3840X	EWP-WX3820X EWP-WX3840X	No

 

RIPng tasks at a glance

To configure RIPng, perform the following tasks:

1.     Configuring basic RIPng

2.     (Optional.) Configuring RIPng route control

¡     Configuring an additional routing metric

¡     Configuring RIPng route summarization

¡     Advertising a default route

¡     Configuring received/redistributed route filtering

¡     Setting a preference for RIPng

¡     Configuring RIPng route redistribution

3.     (Optional.) Tuning and optimizing the RIPng network

¡     Setting RIPng timers

¡     Configuring split horizon and poison reverse

¡     Setting the maximum number of ECMP routes

¡     Configuring the RIPng packet sending rate

¡     Setting the interval for sending triggered updates

4.     (Optional.) Enhancing RIPng availability

¡     Configuring RIPng GR

5.     (Optional.) Enhancing RIPng security

¡     Configuring zero field check for RIPng packets

¡     Applying an IPsec profile

Configuring basic RIPng

1.     Enter system view.

system-view

2.     Enable RIPng and enter its view.

ripng [ process-id ]

By default, RIPng is disabled.

3.     Return to system view.

quit

4.     Enter interface view.

interface interface-type interface-number

5.     Enable RIPng on the interface.

ripng process-id enable

By default, RIPng is disabled on the interface.

If RIPng is not enabled on an interface, the interface does not send or receive any RIPng route.

Configuring RIPng route control

Configuring an additional routing metric

About this task

An additional routing metric (hop count) can be added to the metric of an inbound or outbound RIPng route.

·     An outbound additional metric is added to the metric of a sent route, and it does not change the route's metric in the routing table.

·     An inbound additional metric is added to the metric of a received route before the route is added into the routing table, and the route's metric is changed.

Procedure

1.     Enter system view.

system-view

2.     Enter interface view.

interface interface-type interface-number

3.     Specify an inbound additional routing metric.

ripng metricin value

The default additional metric of an inbound route is 0.

4.     Specify an outbound additional routing metric.

ripng metricout value

The default additional metric of an outbound route is 1.

Configuring RIPng route summarization

About this task

RIPng route summarization is interface-based. RIPng advertises a summary route based on the longest match.

RIPng route summarization improves network scalability, reduces routing table size, and increases routing table lookup efficiency.

RIPng advertises a summary route with the smallest metric of all the specific routes.

For example, RIPng has two specific routes to be advertised through an interface: 1:11:11::24 with a metric of a 2 and 1:11:12::34 with a metric of 3. Configure route summarization on the interface, so RIPng advertises a single route 11::0/16 with a metric of 2.

Procedure

1.     Enter system view.

system-view

2.     Enter interface view.

interface interface-type interface-number

3.     Advertise a summary IPv6 prefix.

ripng summary-address ipv6-address prefix-length

By default, no summary IPv6 prefix is configured on the interface.

Advertising a default route

About this task

You can configure RIPng to advertise a default route with the specified cost to its neighbors.

Procedure

1.     Enter system view.

system-view

2.     Enter interface view.

interface interface-type interface-number

3.     Configure RIPng to advertise a default route.

ripng default-route { only | originate } [ cost cost-value ]

By default, RIPng does not advertise a default route.

This command advertises a default route on the current interface regardless of whether the default route exists in the local IPv6 routing table.

Configuring received/redistributed route filtering

About this task

Perform this task to filter received or redistributed routes by using an IPv6 ACL or IPv6 prefix list. You can also configure RIPng to filter routes redistributed from other routing protocols and routes from a specified neighbor.

Procedure

1.     Enter system view.

system-view

2.     Enter RIPng view.

ripng [ process-id ]

3.     Configure a filter policy to filter received routes.

filter-policy { ipv6-acl-number | prefix-list prefix-list-name } import

By default, RIPng does not filter received routes.

4.     Configure a filter policy to filter redistributed routes.

filter-policy { ipv6-acl-number | prefix-list prefix-list-name } export [ protocol [ process-id ] ]

By default, RIPng does not filter redistributed routes.

Setting a preference for RIPng

About this task

Routing protocols each have a preference. When they find routes to the same destination, the route found by the routing protocol with the highest preference is selected as the optimal route. You can manually set a preference for RIPng. The smaller the value, the higher the preference.

Procedure

1.     Enter system view.

system-view

2.     Enter RIPng view.

ripng [ process-id ]

3.     Set a preference for RIPng.

preference { preference }

By default, the preference of RIPng is 100.

Configuring RIPng route redistribution

1.     Enter system view.

system-view

2.     Enter RIPng view.

ripng [ process-id ]

3.     Configure route redistribution.

import-route protocol [ as-number | process-id ] [ allow-direct | cost cost-value ] *

By default, RIPng does not redistribute routes.

4.     (Optional.) Set a default routing metric for redistributed routes.

default cost cost-value

The default metric of redistributed routes is 0.

Tuning and optimizing the RIPng network

Setting RIPng timers

About this task

You can adjust RIPng timers to optimize the performance of the RIPng network.

Restrictions and guidelines

When you adjust RIPng timers, consider the network performance, and perform unified configurations on routers running RIPng to avoid unnecessary network traffic or route oscillation.

Procedure

1.     Enter system view.

system-view

2.     Enter RIPng view.

ripng [ process-id ]

3.     Set RIPng timers.

timers { garbage-collect garbage-collect-value | suppress suppress-value | timeout timeout-value | update update-value } *

The default settings are as follows:

¡     The update timer is 30 seconds.

¡     The timeout timer is 180 seconds.

¡     The suppress timer is 120 seconds.

¡     The garbage-collect timer is 120 seconds.

Configuring split horizon and poison reverse

Restrictions and guidelines for split horizon and poison reverse

When you configure split horizon and poison reverse, following these restrictions and guidelines:

·     If both split horizon and poison reverse are configured, only the poison reverse feature takes effect.

·     Split horizon disables RIPng from sending routes through the interface where the routes were learned to prevent routing loops between neighbors. As a best practice, enable split horizon to prevent routing loops in normal cases.

·     Poison reverse enables a route learned from an interface to be advertised through the interface. However, the metric of the route is set to 16, which means the route is unreachable.

Configuring split horizon

1.     Enter system view.

system-view

2.     Enter interface view.

interface interface-type interface-number

3.     Enable split horizon.

ripng split-horizon

By default, split horizon is enabled.

Configuring poison reverse

1.     Enter system view.

system-view

2.     Enter interface view.

interface interface-type interface-number

3.     Enable poison reverse.

ripng poison-reverse

By default, poison reverse is disabled.

Setting the maximum number of ECMP routes

1.     Enter system view.

system-view

2.     Enter RIPng view.

ripng [ process-id ]

3.     Set the maximum number of ECMP routes.

maximum load-balancing number

By default, the maximum number of RIPng ECMP routes equals the maximum number of ECMP routes, which is configurable by using the max-ecmp-num command.

Configuring the RIPng packet sending rate

About this task

Perform this task to specify the interval for sending RIPng packets and the maximum number of RIPng packets that can be sent at each interval. This feature can avoid excessive RIPng packets from affecting system performance and consuming too much bandwidth.

Procedure

1.     Enter system view.

system-view

2.     Enter RIPng view.

ripng [ process-id ]

3.     Configuring the RIPng packet sending rate.

¡     Execute the following commands in sequence to configure the RIPng packet sending rate in RIPng view:

ripng [ process-id ] [ vpn-instance vpn-instance-name ]

output-delay time count count

By default, an interface that runs the RIPng process sends a maximum of three RIPng packets every 20 milliseconds.

¡     Execute the following commands in sequence to configure the RIPng packet sending rate in interface view:

interface interface-type interface-number

ripng output-delay time count count

By default, an interface uses the RIPng packet sending rate of the RIPng process that it runs.

Setting the interval for sending triggered updates

About this task

Perform this task to avoid network overhead and reduce system resource consumption caused by frequent RIPng triggered updates.

You can use the timer triggered command to set the maximum interval, minimum interval, and incremental interval for sending RIPng triggered updates.

For a stable network, the minimum interval is used. If network changes become frequent, the triggered update sending interval is incremented by the incremental interval × 2n-2 for each triggered update until the maximum interval is reached. The value n is the number of triggered update times.

Procedure

1.     Enter system view.

system-view

2.     Enter RIPng view.

ripng [ process-id ]

3.     Set the interval for sending triggered updates.

timer triggered maximum-interval [ minimum-interval [ incremental-interval ] ]

The default maximum interval is 5 seconds, the default minimum interval is 50 milliseconds, and the default incremental interval is 200 milliseconds.

Configuring RIPng GR

About this task

GR ensures forwarding continuity when a routing protocol restarts or an active/standby switchover occurs.

Two routers are required to complete a GR process. The following are router roles in a GR process:

·     GR restarter—Graceful restarting router. It must have GR capability.

·     GR helper—A neighbor of the GR restarter. It helps the GR restarter to complete the GR process.

After RIPng restarts on a router, the router must learn RIPng routes again and updates its FIB table, which causes network disconnections and route reconvergence.

With the GR feature, the restarting router (known as the GR restarter) can notify the event to its GR capable neighbors. GR capable neighbors (known as GR helpers) maintain their adjacencies with the router within a configurable GR interval. During this process, the FIB table of the router does not change. After the restart, the router contacts its neighbors to retrieve its FIB.

By default, a RIPng-enabled device acts as the GR helper. Perform this task on the GR restarter.

Procedure

1.     Enter system view.

system-view

2.     Enable RIPng and enter RIPng view.

ripng [ process-id ]

3.     Enable the GR capability for RIPng.

graceful-restart

By default, RIPng GR is disabled.

4.     (Optional.) Set the GR interval.

graceful-restart interval interval

The default GR interval is 60 seconds.

Enhancing RIPng security

Configuring zero field check for RIPng packets

About this task

Some fields in the RIPng packet header must be zero. These fields are called zero fields. You can enable zero field check for incoming RIPng packets. If a zero field of a packet contains a non-zero value, RIPng does not process the packets. If you are certain that all packets are trustworthy, disable the zero field check to save CPU resources.

Procedure

1.     Enter system view.

system-view

2.     Enter RIPng view.

ripng [ process-id ]

3.     Enable the zero field check for incoming RIPng packets.

checkzero

By default, zero field check for incoming RIPng packets is enabled.

Applying an IPsec profile

About this task

To protect routing information and prevent attacks, you can configure RIPng to authenticate protocol packets by using an IPsec profile.

An IPsec profile contains inbound and outbound security parameter indexes (SPIs). RIPng compares the inbound SPI defined in the IPsec profile with the outbound SPI in the received packets. Two RIPng devices accept the packets from each other and establish a neighbor relationship only if the SPIs are the same and the relevant IPsec profiles match.

For more information about IPsec profiles, see Security Configuration Guide.

Restrictions and guidelines

You can apply an IPsec profile to a RIPng process or to an interface. If an interface and its process each have an IPsec profile, the IPsec profile applied to the interface takes effect.

Applying an IPsec profile to a process

1.     Enter system view.

system-view

2.     Enter RIPng view.

ripng [ process-id ]

3.     Apply an IPsec profile to the process.

enable ipsec-profile profile-name

By default, no IPsec profile is applied.

Applying an IPsec profile to an interface

1.     Enter system view.

system-view

2.     Enter interface view.

interface interface-type interface-number

3.     Apply an IPsec profile to the interface.

ripng ipsec-profile profile-name

By default, no IPsec profile is applied.

Verifying and maintaining RIPng

Verifying RIPng configuration and running status

Verifying basic RIPng configuration and running status

Perform display tasks in any view.

·     Display configuration information for a RIPng process.

display ripng [ process-id ]

·     Display routes in the RIPng database.

display ripng process-id database [ ipv6-address prefix-length ]

·     Display interface information for a RIPng process.

display ripng process-id interface [ interface-type interface-number ]

·     Display neighbor information for a RIPng process.

display ripng process-id neighbor [ interface-type interface-number ]

·     Display the routing information for a RIPng process.

display ripng process-id route [ ipv6-address prefix-length [ verbose ] | peer ipv6-address | statistics ]

Verifying RIPng availability configuration

Perform display tasks in any view.

Display RIPng GR information.

display ripng [ process-id ] graceful-restart

Clearing statistics for a RIPng process

To clear the statistics for a RIPng process, execute the following command in user view:

reset ripng process-id statistics

Resetting a RIPng process

To reset a RIPng process, execute the following command in user view:

reset ripng process-id process