Cisco Nexus 5600 Series - ip igmp snooping (VLAN)

Configuring MTU Truncation for Each SPAN Session
To reduce the SPAN traffic bandwidth, you can configure the maximum bytes allowed for each replicated
packet in a SPAN session. This value is called the maximum transmission unit (MTU) truncation size. Any
SPAN packet larger than the configured size is truncated to the configured size.
MTU Truncation is not supported for SPAN-on-Drop sessions.Note
Procedure
PurposeCommand or Action
Enters global configuration mode.switch# configure terminal
Step 1
Enters monitor configuration mode and specifies the
SPAN session for which the MTU truncation size is to
be configured.
switch(config) # monitor session
session-number
Step 2
Configures the MTU truncation size for packets in the
specified SPAN session. The range is from 64 to 1518
bytes.
switch(config-monitor) # [no] mtu
Step 3
(Optional)
Displays the status of SPAN sessions, including the
configuration status of MTU truncation, the maximum
switch(config-monitor) # show
monitor session session-number
Step 4
bytes allowed for each packet per session, and the
modules on which MTU truncation is and is not
supported.
(Optional)
Copies the running configuration to the startup
configuration.
switch(config-monitor) # copy
running-config startup-config
Step 5
This example shows how to configure MTU truncation for a SPAN session:
switch# configure terminal
switch(config) # monitor session 3
switch(config-monitor) # mtu
switch(config-monitor) # copy running-config startup-config
switch(config-monitor) #
Configuring the Rate Limit for SPAN Traffic
By configuring a rate limit for SPAN traffic to 1Gbps across the entire monitor session, you can avoid impacting
the monitored production traffic.
Cisco Nexus 5600 Series NX-OS System Management Configuration Guide, Release 7.x
OL-31641-01 183
Configuring SPAN
Configuring MTU Truncation for Each SPAN Session