Cisco Nexus 7000 Series NX-OS System Management Configuration Guide, Release 4.x

Configuring CFS

This chapter describes how to use Cisco Fabric Services (CFS), a Cisco proprietary feature that distributes data, including configuration changes, to all Cisco NX-OS devices in a network.

This chapter includes the following sections:

•Information About CFS

•Licensing Requirements for CFS

•Prerequisites for CFS

•Guidelines and Limitations

•Configuring CFS Distribution

•Verifying the CFS Configuration

•Default Settings

•Additional References

•Feature History for CFS

Information About CFS

You can use CFS over IP (CFSoIP) to distribute and synchronize a configuration on one Cisco device or with all other Cisco devices in your network. CFSoIP provides you with consistent and, in most cases, identical configurations and behavior in your network.

This section includes the following topics:

•Merging Application Databases

•Applications that Use CFS to Distribute Configuration Changes

•CFS Distribution

•CFS Regions

•High Availability

•Virtualization Support

Merging Application Databases

When a new device is detected in your network, CFS manages the merging, or synchronizing, of its configuration with that of the other devices. CFS also coordinates and minimizes the number of merges by designating one device to manage merges per application per region. The other devices do not play any role in the merge process.

During a merger of two networks, their designated managers exchange configuration databases. The application on one of them merges the databases, decides if the merger is successful, and notifies all other devices.

If the merger is successful, the merged database is distributed to all devices in the combined fabric and the entire new fabric emerges in a consistent state. You can recover from a merge failure by starting a distribution from any device in the new fabric. This distribution restores all peers in the fabric to the same configuration database.

Applications that Use CFS to Distribute Configuration Changes

CFS distributes configuration changes for the applications shown in Table 2-2.

CFS Distribution

CFS distributes configuration changes to multiple devices in a defined region or across a complete network.

The following steps provide an overview of how CFS distributes application configurations.

1. You enable CFS to distribute configurations for an application, such as Call Home.

2. You enter a command to change the configuration for a CFS application, such as Call Home.

3. CFS checks if an active fabric lock indicates that a configuration change is already in progress for this application.

Note Only one CFS session for an application can be active at a time. CFS uses locks to enforce this restriction. Distribution is not allowed to start if locks are in place for the application anywhere else in the fabric.

4. One of the following occurs:

–If an active fabric lock exists for this application, CFS rejects the command. No changes are permitted until the existing fabric lock is released.

–If there is not an active fabric lock for this application, then CFS starts a session and locks the fabric for this application.

5. You enter the remaining configuration commands for the application.

6. You commit the configuration by using the commit command.

7. CFS distributes the configuration and releases the lock.

CFS Regions

A CFS region is a user-defined subset of devices for a given feature or application. You will usually define regions to localize or restrict distribution based on devices that are close to one another.

When a network covers many geographies with many different administrators who are responsible for subsets of devices, you can manage the physical scope of an application by setting up a CFS region.

CFS regions are identified by numbers 0 through 200. Region 0 is the default region. You can configure region number 1 through 200.

Note If a feature is moved, that is, assigned to a new region, its scope is restricted to that region and it ignores all other regions for distribution or merging purposes.

You can set up a CFS region to distribute configurations for multiple features. However, on a given device, you can configure only one CFS region at a time to distribute the configuration for a given feature. Once you assign a feature to a CFS region, its configuration cannot be distributed within another CFS region.

Note The default region is used to distribute changes to all devices in a fabric. Region 0 is reserved as the default region and contains every device in the fabric. If you remove an application from a region and do not assign it to a different region, it is added to the default region (region 0).

High Availability

Stateless restarts are supported for CFS. After a reboot or a supervisor switchover, the running configuration is applied. For more information on high availability, see the Cisco Nexus 7000 Series NX-OS High Availability and Redundancy Guide.

Virtualization Support

CFS is configured per VDC.

When you access Cisco NX-OS, it places you in the default VDC unless you specify a different VDC. For more information on VDCs, see the Cisco Nexus 7000 Series NX-OS Virtual Device Context Configuration Guide, Release 4.x.

Licensing Requirements for CFS

Prerequisites for CFS

CFS has the following prerequisites:

•CFS is enabled by default. All devices in the fabric must have CFS enabled or they do not receive distributions.

•If CFS is disabled for an application, then that application does not distribute any configuration and it does not accept a distribution from other devices in the fabric.

Guidelines and Limitations

CFS has the following configuration guidelines and limitations:

•If the virtual port channel (vPC) feature is enabled for your device, do not disable CFS over Ethernet.

Caution CFS over Ethernet must be enabled for the vPC feature to work.

•CFS distributions for application data use directed unicast.

•All CFS over IP enabled devices with similar multicast addresses form one CFS over IP fabric.

•Make sure that CFS is enabled for the applications you want to configure. For detailed information, see the "Enabling CFS Distribution for Applications" procedure.

•Any time you lock a fabric, your username is remembered across restarts and switchovers.

•Any time you lock a fabric, configuration changes attempted by anyone else are rejected.

•While a fabric is locked, the application holds a working copy of configuration changes in a pending database or temporary storage area—not in the running configuration.

•Configuration changes that have not been committed yet (still saved as a working copy) are not in the running configuration and do not display in the output of show commands.

•The working copy overwrites the running configuration when you commit the changes.

•If you start a CFS session that requires a fabric lock but forget to end the session, an administrator can clear the session. For more information, see the "Clearing a Locked Session" procedure.

• CFSoIP and CFSoE are not supported for use together.

•CFS regions can be applied only to CFSoIP and CFSoFC clients.

•An empty commit is allowed if configuration changes are not previously made. In this case, the commit command results in a session that acquires locks and distributes the current database.

•You can only use the commit command on the specific device where the fabric lock was acquired.

Configuring CFS Distribution

This section describes how to configure CFS and includes the following topics:

•Enabling CFS Distribution for Applications

•Specifying a CFS Distribution Mode

•Configuring an IP Multicast Address for CFS Over IP

•Configuring CFS Regions

•Creating and Distributing a CFS Configuration

•Discarding a Configuration

•Disabling CFS Distribution Globally

Enabling CFS Distribution for Applications

This section includes the following topics:

•Enabling CFS to Distribute Call Home Configurations

•Enabling CFS to Distribute RADIUS Configurations

•Enabling CFS to Distribute TACACS+ Configurations

•Enabling CFS to Distribute Role Configurations

•Enabling CFS to Distribute NTP Configurations

Note See the Cisco Nexus 7000 Series NX-OS Security Configuration Guide, Release 4.x for more information on CFS for RADIUS, TACACS+, and roles. See Chapter 6, "Configuring Smart Call Home" for more information on Call Home, and see Chapter 3, "Configuring NTP" for more information on NTP.

Enabling CFS to Distribute Call Home Configurations

You can enable CFS to distribute Call Home configurations.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. callhome

3. distribute

4. show application_name status

5. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

This example shows how to enable CFS to distribute Call Home configurations:

switch(config)# callhome 

switch(config-callhome)# distribute

switch(config-callhome)# show callhome status

Distribution : Enabled

switch(config-callhome)# copy running-config startup-config

[########################################] 100%

Enabling CFS to Distribute RADIUS Configurations

You can enable CFS to distribute RADIUS configurations.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. radius distribute

3. show radius status

4. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

This example shows how to enable CFS to distribute RADIUS configurations:

switch(config)# radius distribute

switch(config)# show radius status

Distribution : Enabled

switch(config)# copy running-config startup-config

[########################################] 100%

Enabling CFS to Distribute TACACS+ Configurations

You can enable CFS to distribute TACACS+ configurations.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. tacacs+ distribute

3. show tacacs+ status

4. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

This example shows how to enable CFS to distribute TACACS+ configurations:

switch(config)# tacacs+ distribute

switch(config)# show tacacs+ status

Distribution : Enabled

Last operational state: No session

switch(config)# copy running-config startup-config

[########################################] 100%

Enabling CFS to Distribute Role Configurations

You can enable CFS to distribute role configurations.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. role distribute

3. show role status

4. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

This example shows how to enable CFS to distribute Call Home configurations:

switch(config)# role distribute

switch(config)# show role status

Distribution : Enabled

switch(config)# copy running-config startup-config

[########################################] 100%

Enabling CFS to Distribute NTP Configurations

You can enable CFS to distribute NTP configurations.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. ntp distribute

3. show application_name status

4. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

This example shows how to enable CFS to distribute Call Home configurations:

switch(config)# ntp distribute

switch(config)# show ntp status

Distribution : Enabled

switch(config)# copy running-config startup-config

[########################################] 100%

Specifying a CFS Distribution Mode

You can specify and enable a CFS distribution mode (Ethernet or IPv4).

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. cfs [eth | ipv4] distribute

3. show cfs status

4. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

Configuring an IP Multicast Address for CFS Over IP

For CFS protocol-specific distributions, such as the keepalive mechanism for detecting network topology changes, use the IP multicast address to send and receive information.

You can configure the IP multicast address used to distribute CFS over IP for either of the following:

•IPv4—The default IPv4 multicast address is 239.255.70.83.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

You must disable CFS IP distribution before changing the multicast address.

SUMMARY STEPS

1. config t

2. no cfs [ipv4] distribute

3. cfs [ipv4] mcast-address ip_address

4. show cfs status

5. copy running-config startup-config

DETAILED STEPS

switch(config)# no cfs ipv4 distribute

switch(config)# copy running-config 
startup-config

Configuring CFS Regions

This section describes how to create and configure a CFS region and includes the following topics:

•Creating a CFS Region

•Moving an Application to a Different Region

•Removing an Application from a Region

•Deleting a CFS Region

Creating a CFS Region

You can create a CFS region and add an application, such as Call Home, to it.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. cfs region region_number

3. application_name

4. show cfs region brief

5. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

Moving an Application to a Different Region

You can move an application to a different region, for example, you can move NTP from region 1 to region 2.

Note When an application is moved, its scope is restricted to the new region; it ignores all other regions for distribution or merging purposes.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. cfs region region_number

3. application_name

4. show cfs region

5. copy running-config startup-config

DETAILED STEPS

switch(config-cfs-region)# show cfs 
region name callhome

switch(config)# copy running-config 
startup-config

This example shows how to move the Call Home application to CFS region 2:

switch# config t

switch(config)# cfs region 2

switch(config-cfs-region)# callhome

switch(config-cfs-region)# show cfs region name callhome

Region-ID  : 2

Application: callhome

Scope      : Physical-fc-ip

-------------------------------------------------------------------------

 Switch WWN              IP Address

-------------------------------------------------------------------------

 20:00:00:22:55:79:a4:c1 172.28.230.85                           [Local]

                         switch                                  

Total number of entries = 1

switch(config-cfs-region)# 

Removing an Application from a Region

You can remove an application from a region. Removing an application from a region is the same as moving the application back to the default region, The default region is usually region 0. This action brings the entire fabric into the scope of distribution for the application.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. cfs region region_number

3. no application_name

4. Repeat Step 3 for each application you want to remove from this region.

5. show cfs region brief

6. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

Deleting a CFS Region

You can delete a region and move all included applications back to the default region.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. no cfs region region_number

3. show cfs region brief

4. show cfs application name application-name

5. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

Creating and Distributing a CFS Configuration

You can create a configuration change for an application and then distribute it to its application peers.

Caution If you do not commit the changes, they are not distributed and saved in the running configuration of application peer devices.

Caution If you do not save the changes to the startup configuration in every application peer device where distributed, then changes are retained only in their running configurations.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. application_name

3. application_command

4. Repeat Step 3 for each configuration command you want to make.

5. show application_name status

6. commit

7. copy running-config startup-config

DETAILED STEPS

switch(config)# copy running-config 
startup-config

This example shows how to configure and distribute the contact information for Call Home:

switch# config t

Enter configuration commands, one per line. End with CNTL/Z.

switch(config)# snmp-server contact personname@companyname.com

switch(config)# callhome

switch(config-callhome)# email-contact admin@Mycompany.com

switch(config-callhome)# phone-contact +1-800-123-4567

switch(config-callhome)# street-address 123 Anystreet st. Anytown,AnyWhere

switch(config-callhome)# commit

switch(config-callhome)# copy running-config startup-config

[######################################] 100%

switch(config-callhome)#

Clearing a Locked Session

You can clear a lock held by an application from any device in the fabric.

You must have admin permissions to release a lock.

Caution When you clear a lock in the fabric, any pending configurations in any device in the fabric are discarded.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. show application_name  status

3. clear application_name  session

4. show application_name  status

DETAILED STEPS

Discarding a Configuration

You can discard configuration changes and release the lock.

Caution If you discard configuration changes, the application flushes the pending database and releases locks in the fabric.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

1. application_name abort

2. show application_name session status

DETAILED STEPS

switch(config)# no cfs distribute

This will prevent CFS from distributing the 
configuration to other switches.

Are you sure? (y/n)  [n] y

Disabling CFS Distribution Globally

You can disable CFS distribution for a device, isolating the applications using CFS from fabric-wide distributions while maintaining physical connectivity.

When CFS is globally disabled on a device, CFS operations are restricted to the device and all CFS commands continue to function as if the device were physically isolated.

BEFORE YOU BEGIN

Make sure that you are in the correct VDC. To change the VDC, use the switchto vdc command.

SUMMARY STEPS

1. config t

2. no cfs distribute

3. show cfs status

4. copy running-config startup-config

DETAILED STEPS

switch(config)# no cfs distribute

This will prevent CFS from distributing the 
configuration to other switches.

Are you sure? (y/n)  [n] y

switch(config)# copy running-config 
startup-config

Verifying the CFS Configuration

To display the CFS configuration information, perform one of the following tasks:

Default Settings

Table 2-2 lists the default settings for CFS parameters.

Additional References

For additional information, see the following sections:

•Related Documents

•MIBs

Related Documents

MIBs

Feature History for CFS

This section provides the CFS release history.