Port Channeling
Introduction
Port Channels refer to the aggregation of multiple physical
interfaces into one logical interface to provide higher aggregated
bandwidth, load balancing, and link redundancy. Port Channel scan connect to
interfaces across switching modules, so a failure of a switching module cannot bring
down the Port Channel link.
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| Port Channel |
About Port Channeling and Trunking
Trunking is a commonly used storage industry term. However, the
Cisco NX-OS software and
• Port Channeling enables several physical links to be combined
into one aggregated logical link.
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| Trunking |
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| Port channeling and Trunking |
• Trunking enables a link transmitting frames in the EISL format
to carry (trunk) multiple VSAN
• Port Channeling—Interfaces can be channeled between the
following sets of ports:
– E ports and TE ports
– F ports and NP ports
– TF ports and TNP ports
• Trunking—Trunking permits carrying traffic on multiple VSANs
between switches. See the Cisco MDS 9000 Family NX-OS Fabric Configuration
Guide.
• Both Port Channeling and trunking can be used between TE ports
over EISLs.
About Port Channel Modes
There are two types of Port channel modes.
1. ON (Default)
2. Active
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| Differences between ON and Active modes |
Restrictions
Cisco MDS 9000 Family switches support the following number of
Port Channels per switch:
• Switches with only Generation 1 switching modules do not support
F and TF Port Channels.
• Switches with Generation 1 switching modules, or a combination
of Generation 1 and
• Switches with only Generation 2 switching modules or Generation
2 and Generation 3
• A Port Channel number refers to the unique identifier for each
channel group. This number
Port Channel Configuration
Port Channels are created with default values. You can change the
default configuration just like
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| Port Channel Configurations |
About Port Channel Configuration
Before configuring a Port Channel, consider the following
guidelines:
• Configure the Port Channel across switching modules to implement
redundancy on switching
• Ensure that one Port Channel is not connected to different sets
of switches. Port Channels
If you misconfigure Port Channels, you may receive a
misconfiguration message. If you receive
A Port Channel error is detected if the following requirements are
not met:
• Each switch on either side of a Port Channel must be connected
to the same number of
• Each interface must be connected to a corresponding interface on
the other side.
• Links in a Port Channel cannot be changed after the Port Channel
is configured. If you change
If all three conditions are not met, the faulty link is disabled.
Enter the show interface command
for that interface to verify that the Port Channel is
Creating a Port Channel
1. Enters
configuration mode.
Switch # config t
2. Configures the
specified Port Channel (1) using the default ON mode.
Switch (config) # interface
port-channel 1
3. Configures the ACTIVE mode.
Switch (config-if) # channel mode
active
4. Reverts to the default ON mode.
Switch (config-if) # no channel mode
active
5. Deletes the specified Port Channel (1), its associated
interface mappings, and the hardware associations for this Port Channel.
Switch (config) # no interface
port-channel 1
Port-channel 1 deleted and all its members disabled
You can add or remove a physical interface (or a range of
interfaces) to an existing Port Channel.
The compatible parameters on the configuration are mapped to the
Port Channel. Adding an
Removing an interface from a Port Channel decreases the channel
size and bandwidth of the
You can add a physical interface (or a range of interfaces) to an
existing Port Channel. The
A port can be configured as a member of a static Port Channel
only if the following configurations are the same in the port and the Port
Channel:
Speed
Mode
Rate mode
Port VSAN
Trunking mode
Allowed VSAN list or VF-ID list
Compatibility Check
A compatibility check ensures that the same parameter settings are
used in all physical ports in
The check ensures that the following parameters and settings match
at both ends of a Port Channel:
• Capability parameters (type of interface, Gigabit Ethernet at
both ends, or Fibre Channel at
• Administrative compatibility parameters (speed, mode, rate mode,
port VSAN, allowed VSAN
To add an interface to a Port Channel, follow these steps:
1. Configures the
specified port interface (fc1/15).
Switch (config) # interface fc1/15
2. Adds physical Fibre Channel port 1/15 to channel group 15.
If channel group 15 does not
Switch (config-if) # channel-group 15
To add a range of ports to a Port Channel, follow these steps:
1. Configures the
specified range of interfaces. In this example, interfaces from 1/1 to 1/5 are
configured.
Switch (config) # interface fc1/1
– 5
2. Adds physical
interfaces 1/1, 1/2, 1/3, 1/4, and 1/5 to channel group 2. If channel group
If the compatibility check is successful, the interfaces are
operational and the corresponding states apply to these interfaces.
Switch (config-if) # channel-group 2
3. Deletes the physical Fibre Channel interfaces in channel
group 2.
Switch (config-if) # no channel-group
2
Enabling and Configuring Auto creation
1. Enters the
configuration mode for the selected interface(s).
Switch (config) # interface fc8/13
2. Automatically creates the channel group for the selected
interface(s).
Switch (config- if) # channel-group auto
3. Disables the auto creation of channel groups for this
interface, even if the system default
Switch (config- if) # no channel-group auto
Some useful commands
Displays the Port Channel Summary
Switch # show
port-channel summary
----------------------------------------------------------------
Interface Total Ports Oper Ports First
Oper Port
----------------------------------------------------------------
port-channel 77 2
0 --
port-channel 78 2
0
--
port-channel 79 2
2
fcip200
Displays the Port Channel Configured in the Default ON Mode
Switch # show
port-channel database
port-channel 77
Administrative channel mode is on
Operational channel mode is on
Last membership update succeeded
2 ports in total, 0 ports up
Ports: fcip1 [down]
fcip2 [down]
port-channel 78
Administrative channel mode is on
Operational channel mode is on
Last membership update succeeded
2 ports in total, 0 ports up
Ports: fc2/1 [down]
fc2/5 [down]
port-channel 79
Administrative channel mode is on
Operational channel mode is on
Last membership update succeeded
First operational port is fcip200
2 ports in total, 2 ports up
Ports: fcip101 [up]
fcip200 [up] *
Displays the Port Channel Configured in the ACTIVE Mode
port-channel 77
Administrative channel mode is active
Operational channel mode is active
Last membership update succeeded
2 ports in total, 0 ports up
Ports: fcip1 [down]
fcip2 [down]
port-channel 78
Administrative channel mode is active
Operational channel mode is active
Last membership update succeeded
2 ports in total, 0 ports up
Ports: fc2/1 [down]
fc2/5 [down]
port-channel 79
Administrative channel mode is active
Operational channel mode is active
Last membership update succeeded
First operational port is fcip200
2 ports in total, 2 ports up
Ports: fcip101 [up]
fcip200 [up] *
Displays the Consistency Status without Details
Switch # show
port-channel consistency
Database is consistent
Displays the Consistency Status with Details
Switch # show
port-channel consistency detail
Displays the Port Channel Usage
Switch # show
port-channel usage
Displays the Port Channel Compatibility
Switch # show
port-channel compatibility-parameters
Displays Auto created Port Channels
Switch # show interface
fc1/1
Displays the Specified Port Channel Interface
Switch # show
port-channel database interface port-channel 128
Displays the Port Channel Summary
Switch # show
port-channel summary