This Article is a step-by-step guide showing how to configure a packet capture on an NPM physical port.
Some troubleshooting techniques require that you dump packets at the NPM physical port level. It is possible to dump traffic on all NPM-86xx and later versions. In addition to traffic dump, it is also possible to perform actions such as mirroring traffic.
You can use the
acl-interface command to apply multiple select filters such as traffic direction, VLAN, ether type, source/destination mac address, and more.
The following example presents all required commands to complete traffic dump on NPM with or without any filtering. For more options, please refer to XOS Configuration Guide and the XOS Command Reference Guide.
Please note: When doing NPM captures on NPM-86xx modules, there is a traffic limitation for 10Gb interfaces. Please see article titled "Using the "capture" acl-interface-mapping functionality on an NPM-86xx 10gpbs interface to eth2 for tcpdump reduces the NPM's throughput for that 10gbps port to 1gbps."
Such limitation on NPM-86xx also applies when selecting multiple 1Gb physical interfaces or a group interface consisting of 1Gb interfaces -> total current aggregate traffic of all these interfaces must be below 1Gb/sec to avoid traffic impact. NPM96xx modules don't have such limitation.
To dump traffic:
1.Login to NPM in question. When ACL is configured for physical interfaces of different NPMs, you need to login to each of them: x80r51# unix su [root@X80r51 admin]# telnet npm<number>