Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?


Monitoring and Troubleshooting Softwires

Ping and Traceroute for DS-Lite

With Junos OS Release 11.4, you can use the ping and traceroute commands to determine the status of the DS-Lite softwire tunnels:

  • IPv6 ping—The softwire address endpoint on the DS-Lite softwire terminator (AFTR) is usually configured only at the [edit services softwire] hierarchy level; it need not be hosted on any interface. Previous releases of the Junos OS software did not provide replies to pings to the IPv6 softwire address when the AFTR was not configured on a specific interface or loopback. An IPv6 ping enables the softwire initiator (B4) to verify the softwire address of the AFTR before creating a tunnel.

  • IPv4 ping—A special IPv4 address,, is reserved for the AFTR. Previous releases of the Junos OS did not respond to any pings sent to this address. A B4 and other IPv4 nodes can now ping to this address to determine whether the DS-Lite tunnel is working.

  • Traceroute—The AFTR now generates and forwards traceroute packets over the DS-Lite tunnel.


No additional CLI configuration is necessary to use the new functionality.

Monitoring Softwire Statistics


You can review softwire global statistics by using the show services softwire or show services softwire statistics command.


Monitoring CGN, Stateful Firewall, and Softwire Flows


Use the following commands to check the creation of the softwires, pre-NAT flows, and post-NAT flows. Output can be filtered using more specific fields such as AFTR or B4 address or both for DS-Lite, and softwire-concentrator or softwire-initiator or both for 6rd.

  • show services stateful-firewall flows

  • show services softwire flows