Configuring Port Pacing

This chapter describes how to configure Port Pacer and includes the following section.

Information About Port Pacing

The Fibre Channel Port Pacer is supported only on Cisco MDS 9513 and MDS 9710 switches. The Port Pacer is designed to pace the number of mode F ports that come up simultaneously so that ports are brought up in a phased manner.

During an F port start up, the Port Pacer informs the F Port server that a port is starting up. The Port Pacer waits for the F port server to receive FLOGIs and FDISCs on that port. The Port Pacer attempts to bring up concurrent-ports number of ports simultaneously. However, after the F port server informs the Port Pacer that it has received FLOGI and FDISC for that port, and then the Port Pacer completes the port bring up and updates the port status as up. Subsequently, the next port is attempted for starting up.

By default, F port pacing is disabled. After enabling port pacing, number of FLOGI or FDISC received on the port are being tracked. In the case of all FLOGI or FDISC successfully logged in, which would take few seconds, another set of concurrent ports are brought up. At any given time, FLOGI is processed only for configured concurrent ports. This feature is useful in case of zero FLOGI retries in the hosts.

Guidelines and Limitations

Following are the recommended guidelines and requirements for enabling the Port Pacer:

  • Port pacing configurations are supported only for admin port mode F.
  • Concurrent-ports port-number needs to be set depending upon the topology and set this value on how many F ports can be brought up simultaneously.

Configuring Port Pacer

This section includes the following topics:

Enabling Port Pacing

note.gif

Note ●blank.gif Port pacing configuration is supported only for admin port mode F.

  • Port pacing command is a system wide command applicable for all admin port mode F ports.

 

Detailed Step

To enable the port pacer, perform these steps:

 

Command
Purpose

Step 1
switch# configure terminal

Enters configuration mode.

Step 2

switch# (config)# system port pacer mode F interface-login-threshold 10 concurrent-ports 1

switch(config)#

Enables the pacer mode for F port with concurrency of 1 and threshold set as 10.

interface-login-threshold specifies the number of FLOGI or FDISC expected on a port.

concurrent-ports specifies the number of admin port mode F ports that can be brought up simultaneously.

Disabling the Port Pacing Configuration

Detailed Step

To disable the port pacing configuration, follow these steps:

 

Command
Purpose

Step 1
switch# configure terminal

Enters configuration mode.

Step 2

switch# (config)# no system port pacer mode F interface-login-threshold 10 concurrent-ports 1

switch(config)#

Disables the pacer mode for F port.