show ports buffer

show ports port_list buffer


Displays the packet buffer organization for the specified ports.

Syntax Description

port_list Optionally specifies the list of ports, or slots and ports, for which packet buffer information is displayed. If the port_list is omitted then packet buffer information is displayed for all ports in the system.



Usage Guidelines

This command shows the packet buffer organization for the specified ports.

The port_list can span multiple ranges. The packet buffer description for each such port range is displayed.

Since ports and packet buffer are grouped by the hardware, the command displays the range of ports that share the same packet buffer.

The Total Packet Buffer Size for the port range is displayed in bytes, along with an indication of whether or not the user has configured over-commitment of the packet buffer (not overcommitted by default).

The amount of Reserved Buffer allocated to each port and QoS (Quality of Service) Profile is shown for the ports in the user-specified port_list. To configure the reserved buffer, use the configure qosprofile qosprofile maxbuffer percentage ports port_list command.

The Total Shared Buffer Size displayed is the Total Packet Buffer Size minus the total Reserved Buffer allocated to all ports and QoS profiles in the port range. Note that some packet buffer is also reserved to internal ports.  

For each port, the maximum of the Total Shared Buffer Size that the port is allowed to use (Max Shared Buffer Usage) is shown both as an absolute number of bytes and as a percentage of the Total Shared Buffer Size. A port‘s Max Shared Buffer Usage may be configured using the command   configure ports {port_list} shared-packet-bufferpercentage  

Note the configured percentage may be different than the displayed percentage. This is because more recent hardware can only allocate shared packet buffer in steps, while older hardware can precisely allocate the requested percentage.  

The more recent hardware dynamically adjusts each port‘s shared buffer usage limit based on simultaneous usage by multiple ports and QoS profiles, automatically providing fair usage of the shared buffer among the ports and QoS profiles that are currently demanding buffer space. This allows larger packet buffer usage bursts on a port when other ports are not using shared buffer. This dynamic adjustment cannot be observed with this command since only the maximum possible limits are displayed.

The VLAN (Virtual LAN) name is displayed only if that port contains a single VLAN. If the port contains more than one VLAN, then the number of VLANs is displayed.

The tag value may be associated with either a VMAN or a VLAN.


This command was first available in ExtremeXOS 15.3.

Platform Availability

This command is available on the Summit X450-G2, X460-G2, X670-G2, X770, and ExtremeSwitching X440-G2, X620, X690, X870 series switches.