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    Example: Configuring Broadband Gateway Exception Handling Parameters

    This example shows how to configure exception handing parameters on the MobileNext Broadband Gateway. Both IP reassembly and IPv6 advertisement parameters are configured.


    This example uses the following hardware and software components:

    • An MX chassis equipped with session Dense Port Concentrators (DPCs) and three interface Packet Forwarding Engines (housed in DPCs or Modular Port Concentrators [MPCs]).
    • Junos OS Mobility package

    Before you begin:

    • Install the chassis hardware.
    • Configure the chassis, as well as interfaces, anchors, and (optionally) redundancy.


    There are four exceptions to the general rule that user packets flow only through interface Packet Forwarding Engine hardware:

    • Anchor Packet Forwarding Engine failovers (N:1)
    • Reassembly of GPRS tunneling protocol, user plane (GTP-U) and mobility control plane (for instance, authentication, authorization, and accounting [AAA]) fragments
    • IPv6 router advertisements and router solicitation packet handling
    • GTP-U error indication generation

    The first and last items have no configurable parameters. This example configures parameters for IP fragment reassembly and IPv6 router advertisements. The IP fragment reassembly parameters are configured in reassembly-profile-one (you can have multiple reassembly profiles) and applied to the gateway (MBG1). All of the statements in this example use the default values.


    The parameters for IP fragment reassembly and IPv6 router advertisements are configured by:

    CLI Quick Configuration

    [edit services ip-reassembly reassembly-profile-one]set timeout 2 # The default (seconds) set max-reassembly-pending-packets 100 # The default[edit unified-edge gateways ggsn-pgw MBG1]set ip-reassembly reassembly-profile-one # You can apply only one profile to a gateway[edit unified-edge gateways ggsn-pgw MBG1 ipv6-router-advertisement]set current-hop-limit 2 # All statements use defaultsset maximum-advertisement-interval 21600set maximum-initial-advertisement-interval 10set maximum-initial-advertisements 10set minimum-advertisement-interval 16200set reachable-time 0set retransmission-timer 100set router-lifetime 21840

    Step-by-Step Procedure


    From configuration mode, confirm your configuration by entering the show command at the various hierarchy levels. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

    For brevity, these show command outputs include only the configuration that is relevant to this example.

    show services ip-reassembly reassembly-profile-onetimeout 2;max-reassembly-pending-packets 100;show unified-edge gateways ggsn-pgw MBG1ip-reassembly-profile {reassembly-profile-one;}show unified-edge gateways ggsn-pgw MBG1 ip-router-advertisementcurrent-hop-limit 2;maximum-advertisement-interval 21600;maximum-initial-advertisement-interval 10;maximum-initial-advertisements 10;minimum-advertisement-interval 16200;reachable-time 0;retransmission-timer 100;router-lifetime 21840;

    After you configure the device, enter commit from configuration mode.


    Verifying the IP Reassembly Configuration


    Verify that IP reassembly exception handling is operating.


    From operational mode, enter the show unified-edge gateways ggsn-pgw ip-reassembly statistics command.


    Non-zero values indicate that reassembly is functioning.

    Note: You must inspect IPv6 router advertisement packets directly to verify configured header field parameters.

    Verifying the Exception Handling Configuration


    Verify that exception handling is operating.


    From operational mode, enter the show unified-edge gateways ggsn-pgw exception-handling statistics command.

    Note: You can clear these statistics with the clear unified-edge gateways ggsn-pgw exception-handling statistics command.


    Non-zero values indicate that exception handling is functioning.

    Published: 2011-11-16