Avaya 8800 Troubleshooting Manual page 40

Troubleshooting tool fundamentals
• Flow control packets can be issued if port performance is affected while PCAP is
enabled.
• When setting capture-filter parameters for PCAP, a value of 0 is accepted when setting
the range of values. The value of 0 disables the filter parameter (a value of 0 means the
filter parameter is disabled). Do not use 0 in setting a range of values in a filter
parameter.
• When the secondary CPU cycles in the PCAP engine are used for packet capturing, and
if the packet incoming rate is high (about 200 Mbps), the log messages and certain CLI
commands executed in the Secondary CPU are queued. This state is recovered after the
packet capturing is completed. For immediate recovery, disable PCAP on the individual
ports in the primary CPU on which packets are to ingress. The packets captured until this
time are stored in the buffer.
• To autosave using an anonymous FTP session to a Windows system, first create a /pub
subdirectory in the c: directory or the drive which is the default for the FTPserver.
• PCAP uses two levels of filtering to capture packets: one at the hardware level and one
at the software level. The hardware level uses the existing IP filters; the software level
uses capture filters. Use the config ethernet <ports> pcap add set command
to add IP filters for the specified port for PCAP and for regular IP traffic filtering. When
you use the config ethernet <ports> pcap info command, you may see filter
set values that are specific to IP traffic filters only.
Use the config ethernet <ports> pcap enable command to enable or disable
PCAP on the port. When you use the config ethernet <ports> pcap info
command, the information displayed for the enable parameter refers to PCAP only (that
is, if enable is set to true, this means that PCAP is enabled for the specified interface).
• If you use an IP filter as a PCAP filter to capture packets, then you disable PCAP globally
and at the port level, the IP filter remains active.
• To restore the PCAP configuration file after a SF/CPU failover, you must source the
configuration file after the secondary CPU becomes the master. Otherwise, the PCAP
configuration file is not loaded.
• Globally disabling PCAP increases the number of packets dropped in hardware unless
you also disable PCAP on the port. To disable PCAP on the port, use the config
<ethernet> <ports> pcap command.
• When the PCAP buffer fills up, a standby SF/ CPU exception can occur. The exception
only occurs if you use a console connection to the standby SF/CPU. This only occurs
when the autosave feature is enabled and is set to transfer to a network device. The issue
does not occur when you save to a PCMCIA card.
Because the PCAP feature is based on the mirroring capabilities of the I/O ports, limitations
that apply to port mirroring also apply to PCAP. These limitations include
• PCAP cannot be enabled on a port that has port mirroring currently enabled.
• PCAP cannot be enabled if PCAP or port mirroring is enabled on any other port on the
same OctaPID. For 10/100 ports, there is one OctaPID for every 8 ports. For example,
ports 1-8 use one OctaPID, ports 9-16 use another OctaPID, and ports 17-24 use another
OctaPID. For all Gigabit ports, each port has its own OctaPID.
40 Troubleshooting
Comments? infodev@avaya.com
July 2013