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redundancy (M:N Subscriber Redundancy)

Syntax

Hierarchy Level

Description

Enable M:N subscriber group redundancy. This global configuration applies to all subscribers in redundancy groups across the chassis.

For dual-stack subscribers, you must configure both virtual IPv4 and virtual IPv6 addresses on the interface.

Options

interface interface-name

Identify the interface name for the logical access interface for the subscriber redundancy group covered by M:N redundancy.

Note:

You must configure the names for all such interfaces on the chassis for all redundancy groups.

For VRRP redundancy, only ge and xe interfaces are supported for the underlying physical interface. Ethernet connections can be untagged, single-tagged, or double-tagged.

For pseudowire redundancy, only pseudowire interfaces are supported for the underlying physical interface.

Note:

You cannot configure an interface for redundancy if it already has active non-DHCP subscribers. If the interface has existing DHCP subscribers, then redundancy is enabled for those subscribers.

local-inet-address v4-address

(Pseudowires only) Local IP address for the associated pseudowire interface. This address must match one of the access-facing GE interface addresses. It is unique per redundancy group identified by the psx.0 interface. The DHCP relay agent uses this address as the giaddr for DHCP messages sent to a DHCP server. For dynamic subscriber Interfaces, this address is the same as the preferred-source address (the unnumbered address derived from the access-facing GE interface).

local-inet6-address v6-address

(Pseudowires only) Local IPv6 address for the associated pseudowire interface. This address must match one of the access-facing GE interface addresses. It is unique per redundancy group identified by the psx.0 interface. The DHCP relay agent uses this address as the linkaddr for DHCP messages sent to a DHCP server. For dynamic subscriber Interfaces, this address is the same as the preferred-source address (the unnumbered address derived from the access-facing GE interface).

no-advertise-routes-on-backup

(Optional) Suppress advertisement of subscriber access routes or framed routes at the backup BNG towards the core or install the routes in the forwarding table. The routes are added to the routing table when the primary BNG fails over to the backup BNG. This option applies to all subscribers that are covered by redundancy on the chassis and that log in after you configure the option. Existing subscribers are not affected.

Best Practice:

We recommend that you always configure no-advertise-routes-on-backup when you use the non-aggregated mode of address allocation. In this mode, the DHCP server uses a common pool for all redundant subscribers and possibly all non-redundant subscribers. This mode increases the routing services overhead due to the number of routes being advertised for all subscribers. It increases the size of the routing table on the core side and can increase core-side convergence if a DHCP relay agent fails. It also increases downstream traffic convergence. The no-advertise-routes-on-backup option reduces the number of routes advertised and the associated potential issues.

  • Default: Advertise the access and framed routes to the backup BNG during subscriber login.

protocol

Specify a method for BNG M:N redundancy. You can configure both VRRP and pseudowires when the underlying access interfaces do not overlap between these methods.

  • pseudo-wire—Use pseudowires for redundancy on pseudowire interfaces for L2VPN and Layer 2 circuit-based networks over IP/MPLS.

  • vrrp—Use VRRP for redundancy on GE and XE interfaces.

  • Default: vrrp

shared-key string

(Pseudowires only) Shared key that is used by the topology discovery process to identify a backup pseudowire interface on a peer BNG for a subscriber redundancy group. You configure the same shared-key on the local access interfaces on the primary and backup BNGs for a particular redundancy group. A topology discovery match is achieved when both the query and response messages include the pseudowire local access interface name, the same shared key, and the same transaction ID. You define the shared key as a string of up to 64 characters that you choose. You must not use the shared key for any other peer BNGs.

Note:

If the interface already has non-DHCP subscribers, the router rejects the configuration. The configuration is accepted for existing DHCP relay subscribers.

Note:

You cannot dynamically change a shared key after you have configured a key for a subscriber redundancy group (represented by the pseudowire interface). This means that if you change the value after committing it, the change has no effect. In order to have the change take effect, you must delete the entire redundancy group configuration and then add it back with the new key.

virtual-inet-address virtual-inet-address

(VRRP) IPv4 address for the virtual router. This address is used as the gateway address for all redundancy peers associated with a particular subscriber redundancy group. You must specify the same virtual IP address that you also configure on VRRP so that it can create the virtual router for redundancy.

virtual-inet6-address virtual-inet6-address

(VRRP) IPv6 address for the virtual router. This address is used as the gateway address for all redundancy peers associated with a particular subscriber redundancy group. You must specify the same virtual IP address that you also configure on VRRP so that it can create the virtual router for redundancy.

Required Privilege Level

system—To view this statement in the configuration.

system-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Release 19.2R1.

local-inet-address, local-inet6-address, pseudo-wire, and shared-key options added in Junos OS Release 20.1R1.