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Configuring Next Gen Services DS-Lite Softwires

 

Configuring Next Gen Services Softwire Rules

You configure softwire rules to instruct the router how to direct traffic to the addresses specified for 6rd, DS-Lite, or MAP-E softwire concentrators. Softwire rules do not perform any filtration of the traffic. They do not include a from statement, and the only option in the then statement is to specify the address of the softwire concentrator.

Starting in Junos OS release 19.3R2 6rd softwires are supported. Starting in Junos OS release 20.2, DS-Lite and Mapping of Address and Port with Encapsulation (MAP-E).

You can create a softwire rule consisting of one or more terms and associate a particular 6rd, DS-Lite, or MAP-E softwire concentrator with each term. You can include the softwire rule in service sets along with other services rules.

To configure a softwire rule set:

  1. Assign a name to the rule set.

    For example:

  2. Configure the input and output match directions for the rule set.
  3. Specify the name of the rule to apply if the match in this direction is met.

    For example:

  4. Repeat steps 2 and 3, and 4for the output direction.

Configuring Service Sets for Next Gen Services Softwires

You must include previously defined NAT or stateful firewall softwire rules or a softwire rule set in a service set to enable softwire processing.

Starting in Junos OS release 20.2R1, DS-Lite, MAP-E and 6rd softwires are supported in MX240, MX480, and MX960 routers. MAP-E and 6rd softwires are supported inline on an MPC by specifying the si-1/0/0 interface naming convention. DS-Lite is softwires run on the MX-SPC3 security services card.

To configure service sets for softwires:

  1. Specify a name for the service set.

    For example:

  2. Specify the IPv6 prefix length for the subscriber addresses.

    We support four prefix lengths: 56, 64,96 and 128, which is the default.

  3. For NAT, you can include a NAT rule for flows originated by DS-Lite softwires.Note

    Currently a NAT rule configuration is required with a DS-Lite softwire configuration when you use interface service set configurations; NAT is not required when using next-hop service set configurations. NAT processing from IPv4 to IPv6 address pools and vice versa is not currently supported. FTP, HTTP, and RSTP are supported.

    Note

    With a DS-Lite softwire, if you configure stateful firewall rules without configuring NAT rules, using an interface service set causes the ICMP echo reply messages to not be sent correctly to DS-Lite. This behavior occurs if you apply a service set to both inet and inet6 families. In such a scenario, the traffic that is not destined to the DS-Lite softwire concentrator is also processed by the service set and the packets might be dropped, although the service set must not process such packets.

    To prevent the problem to incorrect processing of traffic applicable for DS-Lite, you must configure a next-hop style service set and not an interface style service set. This problem does not occur when you configure NAT rules with interface service sets for DS-Lite.

    Specify the name of the NAT rule set.

  4. Specify the service interface to be used.
  5. Specify the name of the previously defined softwires rule set that you want to apply to this service set.

See also

Configuring the DS-Lite Softwire

Starting in Junos OS release 20.2R1, you can configure DS-Lite softwires for Next Gen Services on the MX-SPC3 services card.

  1. Specify a name for the DS-Lite softwire.
  2. Specify a name for the DS-Lite softwire.

    For example:

  3. Specify the IPv6 address of the softwire concentrator.Note

    For CGNAT Next Gen Services on the MX-SPC3 security services card, when you configure DS-Lite concentrator, use the following rules:

    • For non-prefix based DS-Lite subscribers, specify the B4 IPv6 address

    • For prefix-based DS-Lite subscribers, specify the IPv6 prefix address

    For example:

  4. You can specify the maximum transmission unit (MTU) for the softwire tunnel automatically or manually.

    1. To manually specify the MTUs for the softwire tunnel:
      Note

      This MTU-v6 option sets the maximum transmission unit when encapsulating IPv4 packets into IPv6. If the final length is greater than the MTU-v4 value, the IPv6 packet is fragmented. This option is mandatory because it depends on other network parameters under administrator control.

  5. Specify the maximum number of flows for the softwire.
  6. (Optional) For prefix-based DS-Lite subscriber softwires, configure the maximum number of subscriber sessions allowed per prefix. You can configure from 0 through 16,384 sessions.
    Note

    You cannot use flow-limit and session-limit-per-prefix in the same DS-Lite configuration.

  7. Configure the size of the IPv4 subnet prefix to which limiting is applied. ipv4prefix=6rd customer edge ipv4
  8. Configure the size of the IPv6 subnet prefix to which limiting is applied. Specify a prefix length of 56, 64, 96, or 128.
    Note

    Ensure that all mappings are cleared before changing the prefix length.

Release History Table
Release
Description
Starting in Junos OS release 20.2, DS-Lite and Mapping of Address and Port with Encapsulation (MAP-E).
Starting in Junos OS release 20.2R1, DS-Lite, MAP-E and 6rd softwires are supported in MX240, MX480, and MX960 routers.
Starting in Junos OS release 20.2R1, you can configure DS-Lite softwires for Next Gen Services on the MX-SPC3 services card.
Starting in Junos OS release 19.3R2 6rd softwires are supported.