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Router Advertisement Proxy

SUMMARY Starting in Junos OS Release 22.1R1, we support Router Advertisement (RA) proxy functionality on SRX Series devices and vSRX 3.0. With this functionality, the device can proxy the RA packets from service provider router to the clients (host).


An IPv6 network deployment usually has one or more upstream routers to delegate IPv6 prefixes through Router Advertisement (RA) to clients. When a client connects to the network, the client starts sending Router Solicitations (RS) IPv6 requests. When clients send, upstream routers either respond with unicast (Layer 2 or Layer 3) RA or with multicast RA. Whenever a new client joins the network, a unicast or a multicast RA is sent to from the router to the client. If it is a multicast packet, then the existing clients also receive the RA, which results in traffic increase. The solution for handling the increased traffic is to enable IPv6 RA proxy to monitor the incoming unsolicited RA and RS packets.

RA proxy functionality conveys all the information that is received from the routers to the clients. The RA proxy information includes the following:

  • Router Preference

  • Router lifetime

  • Reachable time

  • Retransmit timer

  • ICMPv6 Option (Source link-layer address)

  • ICMPv6 Option (MTU)

  • ICMPv6 Option (Prefix information)

  • ICMPv6 Option (Route Information)

  • ICMPv6 Option (DNS Search List)

  • ICMPv6 Option (RDNSS option)


The RA is processed as well as proxied, unless proxying is disabled. Also, when RA proxy is enabled, the RA packets received on the upstream interface proxied to all the downstream interfaces. The RA packets received on the downstream interface are not proxied to all the upstream interfaces.


  • Helps in managemnet of traffic by snooping incoming unsolicited RA and Router Solicitations packets allowing transmission of information from service provider side routers to the clients.

  • Loops are prevented using RA blackout timer.

  • New proxy bit provides an indication that the RA packet is proxied.

Configure RA Proxy

To enable RA proxy on an interface:

  1. Configure the interface as upstream (service provider side interface) for RA proxy:
  2. Configure the interface as downstream (host side interface) for RA proxy:
  3. Configure the list of downstream interfaces for RA proxy:
  4. Configure preference to select configured or proxied parameters for downstream interface.
  5. Configure passive mode option on an interface. If passive mode is configured on the interface, the interface receives and processes RA packets. The interface does not send RAs in (receive-only mode). The commit fails if the interface has both downstream and passive-mode option configured simultaneously. To enable passive mode (RA receive only mode) on an interface:

To view the details of configured RA proxy options listed below, use the show ipv6 router-advertisement.

  • Upstream interfaces

  • Downstream interfaces

  • Proxy flag

  • Proxy blackout timer

  • Passive mode details