Cisco Nexus 5000 Series NX-OS Software Configuration Guide

Timer Configuration Across All VSANs

You can modify Fibre Channel protocol related timer values for the switch.

Caution The D_S_TOV, E_D_TOV, and R_A_ TOV values cannot be globally changed unless all VSANs in the switch are suspended.

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Note If a VSAN is not specified when you change the timer value, the changed value is applied to all VSANs in the switch.

To configure Fibre Channel timers across all VSANs, perform this task:

Timer Configuration Per-VSAN

You can also issue the fctimer for a specified VSAN to configure different TOV values for VSANs with special links such as Fibre Channel. You can configure different E_D_TOV, R_A_TOV, and D_S_TOV values for individual VSANs. Active VSANs are suspended and activated when their timer values are changed.

Note This configuration must be propagated to all switches in the fabric. Be sure to configure the same value in all switches in the fabric.

To configure per-VSAN Fibre Channel timers, perform this task:

:

The following example configures the timer value for VSAN 2:

switch(config#)# fctimer D_S_TOV 6000 vsan 2

Warning: The vsan will be temporarily suspended when updating the timer value This configuration would impact whole fabric. Do you want to continue? (y/n) y

Since this configuration is not propagated to other switches, please configure the same value in all the switches

About fctimer Distribution

You can enable per-VSAN fctimer fabric distribution for all Cisco SAN switches in the fabric. When you perform fctimer configurations, and distribution is enabled, that configuration is distributed to all the switches in the fabric.

You automatically acquire a fabric-wide lock when you enter the first configuration command after you enabled distribution in a switch. The fctimer application uses the effective and pending database model to store or commit the commands based on your configuration.

See “Using Cisco Fabric Services,” for more information on the CFS application.

Enabling or Disabling fctimer Distribution

To enable or disable fctimer fabric distribution, perform this task:

Committing fctimer Changes

When you commit the fctimer configuration changes, the effective database is overwritten by the configuration changes in the pending database and all the switches in the fabric receive the same configuration. When you commit the fctimer configuration changes without implementing the session feature, the fctimer configurations are distributed to all the switches in the physical fabric.

To commit the fctimer configuration changes, perform this task:

Discarding fctimer Changes

After making the configuration changes, you can choose to discard the changes by discarding the changes instead of committing them. In either case, the lock is released.

To discard the fctimer configuration changes, perform this task:

Fabric Lock Override

If you have performed a fctimer fabric task and have forgotten to release the lock by either committing or discarding the changes, an administrator can release the lock from any switch in the fabric. If the administrator performs this task, your changes to the pending database are discarded and the fabric lock is released.

Tip The changes are only available in the volatile directory and are subject to being discarded if the switch is restarted.

To use administrative privileges and release a locked fctimer session, use the clear fctimer session command.

Database Merge Guidelines

When merging two fabrics, follow these guidelines:

• Be aware of the following merge conditions:

– The merge protocol is not implemented for distribution of the fctimer values. You must manually merge the fctimer values when a fabric is merged.

– The per-VSAN fctimer configuration is distributed in the physical fabric.

– The fctimer configuration is only applied to those switches containing the VSAN with a modified fctimer value.

– The global fctimer values are not distributed.

• Do not configure global timer values when distribution is enabled.

Note The number of pending fctimer configuration operations cannot be more than 15. After 15 operations, you must commit or abort the pending configurations before performing any more operations.

See the “CFS Merge Support” section for additional information.

Verifying Configured fctimer Values

Use the show fctimer command to display the configured fctimer values. The following example displays the configured global TOVs:

Note The F_S_TOV constant, though not configured, is displayed in the output of the show fctimer command.

The following example displays the configured TOV for VSAN 10:

Verifying WWN Information

Use the show wwn commands to display the status of the WWN configuration. The following example displays the status of all WWNs:

The following example displays the WWN for a specific switch:

Link Initialization WWN Usage

Exchange Link Protocol (ELP) and Exchange Fabric Protocol (EFP) use WWNs during link initialization. ELPs and EFPs both use the VSAN WWN by default during link initialization. However, the ELP usage changes based on the peer switch’s usage:

• If the peer switch ELP uses the switch WWN, then the local switch also uses the switch WWN.
• If the peer switch ELP uses the VSAN WWN, then the local switch also uses the VSAN WWN.

Configuring a Secondary MAC Address

To allocate secondary MAC addresses, perform this task:

The following example shows how to configure the secondary MAC address:

switch(config)# wwn secondary-mac 00:99:55:77:55:55 range 64

This command CANNOT be undone.

Please enter the BASE MAC ADDRESS again: 00:99:55:77:55:55

Please enter the mac address RANGE again: 64

From now on WWN allocation would be based on new MACs.

Are you sure? (yes/no) no

You entered: no. Secondary MAC NOT programmed

Default Company ID List

All Cisco Nexus 5000 Series switches contain a default list of company IDs that require area allocation. Using the company ID reduces the number of configured persistent FC ID entries. You can configure or modify these entries using the CLI.

The list of company IDs have the following characteristics:

• A persistent FC ID configuration always takes precedence over the list of company IDs. Even if the company ID is configured to receive an area, the persistent FC ID configuration results in the allocation of a single FC ID.
• New company IDs added to subsequent releases are automatically added to existing company IDs.
• The list of company IDs is saved as part of the running and saved configuration.
• The list of company IDs is used only when the fcinterop FC ID allocation scheme is in auto mode. By default, the interop FC ID allocation is set to auto, unless changed.

Tip We recommend that you set the fcinterop FC ID allocation scheme to auto and use the company ID list and persistent FC ID configuration to manipulate the FC ID device allocation.

Use the fcinterop FCID allocation auto command to change the FC ID allocation and the show running-config command to view the currently allocated mode.

• When you enter a write erase, the list inherits the default list of company IDs shipped with a relevant release.

To allocate company IDs, perform this task:

The following example adds a new company ID to the default list.

Verifying the Company ID Configuration

You can view the configured company IDs by entering the show fcid-allocation area command. Default entries are listed first and the user-added entries are listed next. Entries are listed even if they were part of the default list and you later removed them.

The following example displays the list of default and configured company IDs:

You can implicitly derive the default entries shipped with a specific release by combining the list of Company IDs displayed without any identification with the list of deleted entries.

You can also view or obtain the company IDs in a specific WWN by entering the show fcid-allocation company-id-from-wwn command. Some WWN formats do not support company IDs. In these cases, you many need to configure the FC ID persistent entry.

The following example displays the company ID for the specified WWN:

About Interop Mode

Cisco NX-OS software supports the following four interop modes:

• Mode 1— Standards-based interop mode that requires all other vendors in the fabric to be in interop mode.
• Mode 2—Brocade native mode (Core PID 0).
• Mode 3—Brocade native mode (Core PID 1).
• Mode 4—McData native mode.

For information about configuring interop modes 2, 3, and 4, see the Cisco MDS 9000 Family Switch-to-Switch Interoperability Configuration Guide, available at the following location:

http://www.cisco.com/en/US/docs/storage/san_switches/mds9000/interoperability/guide/intopgd.html

Table 1-2 lists the changes in switch operation when you enable interoperability mode. These changes are specific to Cisco Nexus 5000 Series switches while in interop mode.

Configuring Interop Mode 1

The interop mode1 in Cisco Nexus 5000 Series switches can be enabled disruptively or nondisruptively.

Note Brocade’s msplmgmtdeactivate command must explicitly be run prior to connecting from a Brocade switch to either Cisco Nexus 5000 Series switches or to McData switches. This command uses Brocade proprietary frames to exchange platform information, which Cisco Nexus 5000 Series switches or McData switches do not understand. Rejecting these frames causes the common E ports to become isolated.

To configure interop mode 1 in any switch in the Cisco Nexus 5000 Series, perform this task:

Step 1 Place the VSAN of the E ports that connect to the OEM switch in interoperability mode.

Step 2 Assign a domain ID in the range of 97 (0x61) through 127 (0x7F).

Note This is an limitation imposed by the McData switches.

In Cisco Nexus 5000 Series switches, the default is to request an ID from the principal switch. If the preferred option is used, Cisco Nexus 5000 Series switches request a specific ID, but still join the fabric if the principal switch assigns a different ID. If the static option is used, the Cisco Nexus 5000 Series switches do not join the fabric unless the principal switch agrees and assigns the requested ID.

Note When changing the domain ID, the FC IDs assigned to N ports also change.

Step 3 Change the Fibre Channel timers (if they have been changed from the system defaults).

Note The Cisco Nexus 5000 Series, Brocade, and McData FC Error Detect (ED_TOV) and Resource Allocation (RA_TOV) timers default to the same values. They can be changed if needed. The RA_TOV default is 10 seconds, and the ED_TOV default is 2 seconds. Per the FC-SW2 standard, these values must be the same on each switch within the fabric.

Step 4 When making changes to the domain, you may or may not need to restart the domain manager function for the altered VSAN.

• Force a fabric reconfiguration with the disruptive option.

or

• Do not force a fabric reconfiguration.

Verifying Interoperating Status

This section highlights the commands used to verify if the fabric is up and running in interoperability mode.

To verify the resulting status of entering the interoperability command in any switch in the Cisco Nexus 5000 Series, perform this task:

Step 1 Verify the software version.

Step 2 Verify if the interface states are as required by your configuration.

Step 3 Verify if you are running the desired configuration.

Step 4 Verify if the interoperability mode is active.

Step 5 Verify the domain ID.

Step 6 Verify the local principal switch status.

Step 7 Verify the next hop and destination for the switch.

Step 8 Verify the name server information.

Note The Cisco switch name server shows both local and remote entries, and does not time out the entries.