Enabling Passive Monitoring on SONET/SDH Interfaces
The Monitoring Services I and Monitoring Services II PICs are designed to enable IP services. If you have a Monitoring Services PIC and a SONET/SDH PIC installed in an M Series, MX Series, or T Series router, you can monitor IPv4 and IPv6 traffic from another router.
On SONET/SDH interfaces, you enable packet flow monitoring by including the passive-monitor-mode statement:
You can include this statement at the following hierarchy levels:
- [edit interfaces so-fpc/pic/port unit logical-unit-number]
- [edit logical-systems logical-system-name interfaces so-fpc/pic/port unit logical-unit-number]
If you include the passive-monitor-mode statement in the configuration, the SONET/SDH interface does not send keepalives or alarms, and does not participate actively on the network.
On monitoring services interfaces, you enable packet flow monitoring by including the family statement at the [edit interfaces mo-fpc/pic/port unit logical-unit-number] hierarchy level, specifying the inet option:
For conformity with cflowd record structure, you must include the receive-options-packets and receive-ttl-exceeded statements at the [edit interfaces mo-fpc/pic/port unit logical-unit-number family inet] hierarchy level:
For the monitoring services interface, you can configure multiservice physical interface properties. For more information, see Configuring Multiservice Physical Interface Properties and the Junos Services Interfaces Configuration Release 11.2.
Removing MPLS Labels from Incoming Packets
The Junos OS can forward only IPv4 packets to a Monitoring Services PIC. IPv4 packets with MPLS labels cannot be forwarded to a Monitoring Services PIC. By default, if packets with MPLS labels are forwarded to the Monitoring Services PIC, they are discarded. To monitor packets with MPLS labels, you must remove the MPLS labels as the packets arrive on the interface.
You can remove up to two MPLS labels from an incoming packet by including the pop-all-labels statement at the [edit interfaces interface-name sonet-options mpls] hierarchy level:
By default, the pop-all-labels statement takes effect for incoming packets with one or two labels. You can specify the number of MPLS labels an incoming packet must have for the pop-all-labels statement to take effect by including the required-depth statement at the [edit interfaces interface-name atm-options mpls pop-all-labels] hierarchy level:
The required depth can be 1, 2, or [ 1 2 ]. If you include the required-depth 1 statement, the pop-all-labels statement takes effect for incoming packets with one label only. If you include the required-depth 2 statement, the pop-all-labels statement takes effect for incoming packets with two labels only. If you include the required-depth [ 1 2 ] statement, the pop-all-labels statement takes effect for incoming packets with one or two labels. A required depth of [ 1 2 ] is equivalent to the default behavior of the pop-all-labels statement.
When you remove MPLS labels from incoming packets, note the following:
- The pop-all-labels statement has no effect on IP packets with three or more MPLS labels.
- When you enable MPLS label removal, you must configure all ports on a PIC with the same label popping mode and required depth.
- You use the pop-all-labels statement to enable passive monitoring applications, not active monitoring.
- You cannot apply MPLS filters or accounting to the MPLS labels because the labels are removed as soon as the packet arrives on the interface.
