Chapter 47: Configuring Packet Capture - Avaya 1000 Series Configuration Manual

Chapter 47: Configuring Packet Capture

The packet capture feature is used to capture the packets sent and received on any supported interface
in the router. This feature aids in debugging and troubleshooting network traffic issues. Capture format is
libpcap format (version 2.4) supported by the most commonly used third party packet analyzers like
ethereal and tcpdump.
The captured packets will contain all the protocol headers including the L2 header. This feature can be
enabled on a network layer interface while traffic is flowing through the system. Packets can be captured in
inbound and outbound directions, while the default is 'both' when direction is not specified. Packets can
be captured simultaneously on one more L3 interfaces. The packet feature can use filtering rules and
enable a user to view the captured packets. It is possible to specify whether non-ip packets should be
captured on a given device. Packet capture can be disabled on a network layer interface while packet
capture session is ongoing.
The number of packets to be captured and the maximum capture length can be specified. It is possible
to configure the total amount of memory to be reserved for all packet capture sessions configured in the
system, and the max size of the packet capture session on an interface.
It is possible to save the captured packets to a local or remote file and specify whether the packet capture
buffers should be overwritten when the buffer is full.
The following packet capture feature link layers are supported:
• Ethernet physical interfaces
• Ethernet subinterfaces
• Single and multilink PPP bundle interfaces
• Cisco HDLC interfaces
• Frame Relay PVCs
• PCs over multilink FR (FRF.16) bundle interfaces
Important:
PCAP is primarily a debug tool and should be used only in this fashion as it can generate a substantial
amount of output and can use a substantial amount of system resources.
Example
Configuring Packet Capture
SR/debug/pcap> capture cap1
SR/debug/pcap/capture cap1> attach ethernet 0
SR/debug/pcap/capture cap1> count 1000
Avaya Secure Router 1000 Series Configuration Guide December 2010 335