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This chapter contains the following sections:
A port channel is an aggregation of multiple physical interfaces that creates a logical interface. You can bundle up to eight individual active links into a port channel to provide increased bandwidth and redundancy. Port channeling also load balances traffic across these physical interfaces. The port channel stays operational as long as at least one physical interface within the port channel is operational.
You can use static port channels, with no associated aggregation protocol, for a simplified configuration.
A port channel bundles physical links into a channel group to create a single logical link that provides the aggregate bandwidth of up to eight physical links. If a member port within a port channel fails, the traffic previously carried over the failed link switches to the remaining member ports within the port channel.
You can bundle up to eight ports into a static port channel without using any aggregation protocol.
Note |
The device does not support Port Aggregation Protocol (PAgP) for port channels. |
Each port can be in only one port channel. All the ports in a port channel must be compatible; they must use the same speed and duplex mode. When you run static port channels with no aggregation protocol, the physical links are all in the on channel mode.
You can create port channels directly by creating the port channel interface, or you can create a channel group that acts to aggregate individual ports into a bundle. When you associate an interface with a channel group, the software creates a matching port channel automatically if the port channel does not already exist. In this instance, the port channel assumes the Layer 2 configuration of the first interface. You can also create the port channel first. In this instance, the Cisco Nexus 1000V creates an empty channel group with the same channel number as the port channel and takes the default Layer 2 configuration, as well as the compatibility configuration.
Note |
The port channel is operationally up when at least one of the member ports is up and is in the channeling state. The port channel is operationally down when all member ports are operationally down. |
When you add an interface to a port channel group, the following compatibility checks are made before allowing the interface to participate in the port channel:
To view the full list of compatibility checks performed by the Cisco Nexus 1000V, use the show port-channel compatibility-parameters.
You can only add interfaces configured with the channel mode set to on to static port channels. You can configure these attributes on an individual member port. If you configure a member port with an incompatible attribute, the Cisco Nexus 1000V suspends that port in the port channel.
Alternatively, you can force ports with incompatible parameters to join the port channel if the following parameters are the same:
When the interface joins a port channel, some of its individual parameters are removed and replaced with the values on the port channel as follows:
The following interface parameters remain unaffected when the interface joins or leaves a port channel:
Note |
When you delete the port channel, the software sets all member interfaces as if they were removed from the port channel. |
The Cisco Nexus 1000V load balances traffic across all operational interfaces in a port channel by hashing the addresses in the frame to a numerical value that selects one of the links in the channel. Port channels provide load balancing by default. Port channel load balancing uses MAC addresses, IP addresses, or Layer 4 port numbers to select the link. Port channel load balancing uses either source or destination addresses or ports, or both source and destination addresses or ports.
You can configure the load balancing mode to apply to all port channels that are configured on the entire device or on specified modules. The per-module configuration takes precedence over the load-balancing configuration for the entire device. You can configure one load balancing mode for the entire device, a different mode for specified modules, and another mode for the other specified modules. You cannot configure the load balancing method per port channel.
You can configure the type of load balancing algorithm used. You can choose the load balancing algorithm that determines which member port to select for egress traffic by looking at the fields in the frame.
Note |
The default load balancing method uses source MAC addresses. |
You can configure one of the following methods to load balance across the port channel:
When you configure source IP address load balancing, the source MAC address is used to balance the traffic load. When you configure the destination MAC address load balancing method, the traffic load is balanced using the destination MAC address.
When you configure source IP address load balancing, the source MAC address is used to balance the traffic load. When you configure the destination MAC address load balancing method, the traffic load is balanced using the destination MAC address.
The load balancing methods that use port channels do not apply to multicast traffic. Regardless of the method configured, multicast traffic uses the following methods for load balancing with port channels:
To configure port channel load balancing, see the “Configuring Port Channel Load Balancing” procedure on page 5-38.
The Link Aggregation Control Protocol (LACP) allows you to configure up to 16 interfaces into a port channel. A maximum of eight interfaces can be active, and a maximum of eight interfaces can be placed in a standby state. The following figure shows how individual links can be combined into LACP port channels and channel groups as well as function as individual links.
You can offload operation of the LACP from the Virtual Supervisor Module (VSM) to the Virtual Ethernet Ports (VEMs). To prevent a situation where the VSM cannot negotiate LACP with the upstream switch when the VEM is disconnected from the VSM (referred to as headless mode). VEM management of LACP allows it to reestablish port channels after the reboot of a headless VEM.
Individual interfaces in port channels are configured with channel modes. When you run static port channels with no aggregation protocol, the channel mode is always set to on.
You enable LACP for each channel by setting the channel mode for each interface to active or passive. You can configure either channel mode for individual links in the LACP channel group when you are adding the links to the channel group.
The following table describes the channel modes.
Channel Mode | Description |
---|---|
passive |
LACP mode that places a port into a passive negotiating state in which the port responds to LACP packets that it receives but does not initiate LACP negotiation. |
active |
LACP mode that places a port into an active negotiating state in which the port initiates negotiations with other ports by sending LACP packets. |
on |
All static port channels (that are not running LACP) remain in this mode. If you attempt to change the channel mode to active or passive before enabling LACP, the device displays an error message. You enable LACP on each channel by configuring the interface in that channel for the channel mode as either active or passive. When an LACP attempts to negotiate with an interface in the on state, it does not receive any LACP packets and becomes an individual link with that interface; it does not join the LACP channel group. The default port channel mode is on. |
Both the passive and active modes allow LACP to negotiate between ports to determine if they can form a port channel based on criteria such as the port speed and the trunking state. The passive mode is useful when you do not know whether the remote system, or partner, supports LACP.
Ports can form an LACP port channel when they are in different LACP modes if the modes are compatible as in these examples:
This section describes the LACP parameters.
Each system that runs LACP has an LACP system priority value. You can accept the default value of 32768 for this parameter, or you can configure a value between 1 and 65535. LACP uses the system priority with the MAC address to form the system ID and also uses the system priority during negotiation with other devices. A higher system priority value means a lower priority.
Note |
The LACP system ID is the combination of the LACP system priority value and the MAC address. |
Each port that is configured to use LACP has an LACP port priority. You can accept the default value of 32768 for the LACP port priority, or you can configure a value between 1 and 65535. LACP uses the port priority with the port number to form the port identifier.
LACP uses the port priority to decide which ports should be put in standby mode when there is a limitation that prevents all compatible ports from aggregating and which ports should be put into active mode. A higher port priority value means a lower priority for LACP. You can configure the port priority so that specified ports have a lower priority for LACP and are most likely to be chosen as active links, rather than as hot-standby links.
LACP automatically configures an administrative key value that is equal to the channel-group number on each port configured to use LACP. The administrative key defines the ability of a port to aggregate with other ports. A port’s ability to aggregate with other ports is determined by these factors:
You can dynamically redistribute the data traffic by using port channels. This redistribution may result from a removed or added link or a change in the load-balancing scheme. Traffic redistribution that occurs in the middle of a traffic flow can cause misordered frames.
LACP uses the Marker Protocol to ensure that frames are not duplicated or reordered due to this redistribution. The Marker Protocol detects when all the frames of a given traffic flow are successfully received at the remote end. LACP sends Marker PDUs on each of the port-channel links. The remote system responds to the Marker PDU once it receives all the frames received on this link prior to the Marker PDU. The remote system then sends a Marker Responder. Once the Marker Responders are received by the local system on all member links of the port channel, the local system can redistribute the frames in the traffic flow with no chance of misordering. The software supports only Marker Responders.
The following table summarizes the major differences between port channels with LACP enabled and static port channels.
Configurations | Port Channels with LACP Enabled | Static Port Channels |
---|---|---|
Protocol applied |
Enable globally |
Not applicable |
Channel mode of links |
Can be either: |
Can only be On |
Maximum number of links in channel |
16 |
8 |
You use vPC-HM mode to create a port channel when the switch is connected to multiple upstream switches that are not clustered. In the Cisco Nexus 1000V, the port channel is divided into subgroups or logical smaller port channels, each representing one or more uplinks to one upstream physical switch.
Links that connect to the same physical switch are bundled in the same subgroup automatically by using information gathered from the Cisco Discovery Protocol (CDP) packets from the upstream switch. Interfaces can also be manually assigned a specific subgroup.
You use vPC-HM, each vEthernet interface on the VEM is mapped to one of two subgroups in a round-robin method. All traffic from the vEthernet interface uses the assigned subgroup unless it is unavailable, in which case the vEthernet interface fails over to the remaining subgroup. When the original subgroup becomes available again, traffic shifts back to it. Traffic from each vEthernet interface is then balanced based on the configured hashing algorithm.
When multiple uplinks are attached to the same subgroup, you must configure the upstream switch in a port channel with the links bundled together. The port channel must also be configured with the channel-group auto mode on (active and passive modes use LACP).
If the upstream switches do not support port channels, you can use MAC pinning to assign each Ethernet port member to a particular port channel subgroup.
Note |
Do not configure vPC-HM on the Cisco Nexus 1000V when the upstream switch ports that connect to the VEMs have vPC configured. If vPC is configured, the connection can be interrupted or disabled. |
The following figure shows how to use vPC-HM to assign member ports 1 and 2 to subgroup ID 0 and member ports 3 and 4 to subgroup ID 1.
If Cisco Discovery Protocol (CDP) is enabled on the upstream switches, then subgroups are automatically created using information gathered from the CDP packets. If not, you must manually create subgroups.
Static pinning allows you to pin the virtual ports behind a VEM to a particular subgroup within the channel. Instead of allowing round robin dynamic assignment between the subgroups, you can assign (or pin) a static vEthernet interface, control VLAN, or packet VLAN to a specific port channel subgroup. With static pinning, traffic is forwarded only through the member ports in the specified subgroup.
You can also pin vEthernet interfaces to subgroups in interface configuration mode.
If you are connecting to multiple upstream switches that do not support port channels, then MAC pinning is the preferred configuration. MAC pinning divides the uplinks from your server into standalone links and pins the MAC addresses to those links in a round-robin method. This ensures that the MAC address of a virtual machine is never seen on multiple upstream switch interfaces. Therefore no upstream configuration is required to connect the VEM to upstream switches.
MAC pinning does not rely on any protocol to distinguish upstream switches so the configuration is independent of upstream hardware or design.
In case of a failure, the Cisco Nexus 1000V first sends a gratuitous ARP packet to the upstream switch indicating that the VEM MAC address will now be learned on a different link. It also allows for sub-second failover time.
The following figure shows each member port that is assigned to a specific port channel subgroup using MAC pinning.
This feature modifies the existing algorithm for MAC pinning where the port-channel uses the port number (vmnic number) as the subgroup ID for an Ethernet member port.
The new algorithm assigns zero-based logical subgroup IDs to Ethernet member ports. The member port that has the lowest port number (vmnic number) is assigned subgroup ID 0.
The following figure shows each member port that is assigned to a specific port channel subgroup using MAC pinning relative.
Network state tracking for vPC-HM identifies link failures where other detection methods fail, and verifies Layer 2 connectivity between vPC-HM channel subgroups. It is not intended to detect network configuration problems.
Network state tracking selects one uplink interface in each sub group for broadcasting packets to a tracking VLAN. The tracking VLAN is usually the lowest forwarding VLAN for trunk ports and the primary VLAN for promiscuous access ports. The packets that are received back from the network on each subgroup are tracked as are the number of consecutively missed broadcasts. If the missed broadcasts for a sub group exceed the threshold, the port channel is considered to be in split mode. In split mode, the interfaces are marked as inactive, and traffic is pinned to active interfaces.
System messages indicate when a port channel enters or recovers from split mode; and interfaces are marked active or inactive.
Port channels provide high availability by load balancing traffic across multiple ports. If a physical port fails, the port channel is still operational if there is an active member in the port channel.
Port channels support stateful and stateless restarts. A stateful restart occurs on a supervisor switchover. After the switchover, the Cisco Nexus 1000V applies the runtime configuration after the switchover.
Port channeling has the following prerequisites:
Port channeling has the following guidelines and restrictions:
Note |
If you have a separate dedicated NIC for control traffic, these settings are not required. |
Caution |
Disruption of connectivity might result if you configure vPC-HM on the Cisco Nexus 1000V when vPC is also configured on the ports of upstream switches that connect to its VEMs. |
Parameters | Default | ||
---|---|---|---|
Port profile type |
vEthernet |
||
Port profile administrative state |
All ports are disabled. |
||
Port channel |
Admin up |
||
LACP |
Disabled
|
||
Load balancing method for Layer 2 interfaces |
Source and destination MAC address |
||
Load balancing per module |
Disabled |
||
Channel mode |
on |
||
LACP offload (Offloading LACP management to VEMs) |
Enabled
|
||
Network State Tracking: Broadcast interval |
5 seconds |
||
Network State Tracking: Split-network mode action |
repin |
||
Network State Tracking: Maximum threshold miss count |
5 seconds |
||
Network State Tracking: State |
Disabled |
Configuring Port Channels
You can define a port channel in a port profile and, if needed, to configure and pin interface or VLAN subgroups.
Step 1 | Connect to a single upstream switch. See Connecting to a Single Upstream Switch. |
Step 2 | Connect to multiple upstream switches. SeeConnecting to Multiple Upstream Switches. |
Step 3 | Manually configure interface subgroups. See Manually Configuring Interface Subgroups. |
Step 4 | Pin a vEthernet interface to a subgroup. See Pinning a vEthernet Interface to a Subgroup. |
Step 5 | Pin a control or packet VLAN to a subgroup. See Pinning a Control or Packet VLAN to a Subgroup. |
You can configure a port channel whose ports are connected to the same upstream switch. If the ports are connected to multiple upstream switches, see Connecting to Multiple Upstream Switches
.The channel group number assignment is made automatically when the port profile is assigned to the first interface.
This example shows how to configure a port channel that connects to one upstream switch:
switch# configure terminal switch(config)# port-profile AccessProf switch(config-port-prof)# channel-group auto mode on switch(config-port-prof)# show port-profile name AccessProf port-profile AccessProf description: allaccess4 status: disabled capability l3control: no pinning control-vlan: - pinning packet-vlan: - system vlans: none port-group: max ports: 32 inherit: config attributes: channel-group auto mode on evaluated config attributes: channel-group auto mode on assigned interfaces: switch(config-port-prof)#
You can create a port channel that connects to multiple upstream switches.
Caution |
Connectivity may be disrupted for up to 60 seconds if the CDP timer is set to 60 seconds (the default). |
Caution |
The VMs behind the Cisco Nexus 1000V receive duplicate packets from the network for unknown unicasts, multicast floods, and broadcasts if vPC-HM is not configured when port channels connect to two different upstream switches. |
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
||
Step 2 | switch(config)# port-profile [type {ethernet | vethernet}] name | Enters port profile configuration mode for the named port profile.
|
||
Step 3 | switch(config-port-prof)# channel-group auto mode on [sub-group {cdp | manual }] [mac-pinning [ relative]] | Creates a unique asymmetric port channel (also known as vPC-HM) and automatically assigns it when the port profile is assigned to the first interface. Each additional interface that belongs to the same module is added to the same port channel. In VMware environments, a different port channel is created for each module. The following options are also defined:
|
||
Step 4 | switch(config-port-prof)# show port-profile [ brief | expand-interface | usage] [name profile-name] | (Optional) Displays the configuration for verification. |
||
Step 5 | switch(config-port-prof)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to create a port channel that connects to multiple upstream switches that support CDP:
switch# configure terminal switch(config)# port-profile UpLinkProfile2 switch(config-port-prof)# channel-group auto mode on sub-group cdp switch(config-port-prof)# show port-profile name UpLinkProfile2 port-profile UpLinkProfile2 description: type: ethernet status: disabled capability l3control: no pinning control-vlan: - pinning packet-vlan: - system vlans: none port-group: max ports: 32 inherit: config attributes: channel-group auto mode on sub-group cdp evaluated config attributes: channel-group auto mode on sub-group cdp assigned interfaces: switch(config-port-prof)# copy running-config startup-config
This example shows how to create a port channel that connects to multiple upstream switches that do not support CDP:
switch# configure terminal switch(config)# port-profile UpLinkProfile3 switch(config-port-prof)# exit switch(config)# interface ethernet3/2-3 switch(config-if)# sub-group-id 0 switch(config-port-prof)# show port-profile name switch(config-port-prof)# show port-profile name UplinkProfile3 port-profile UplinkProfile3 description: type: ethernet status: enabled capability l3control: no pinning control-vlan: - pinning packet-vlan: - system vlans: none port-group: UplinkProfile3 max ports: - inherit: config attributes: channel-group auto mode on sub-group manual evaluated config attributes: channel-group auto mode on sub-group manual assigned interfaces: switch(config-port-prof)# copy running-config startup-config
This example shows how to create a port channel that connects to multiple upstream switches that do not support port channels:
switch# configure terminal switch(config)# port-profile UpLinkProfile1 switch(config-port-prof)# channel-group auto mode on mac-pinning switch(config-port-prof)# show port-profile name UpLinkProfile1 port-profile UpLinkProfile1 description: type: ethernet status: disabled capability l3control: no pinning control-vlan: - pinning packet-vlan: - system vlans: none port-group: max ports: 32 inherit: config attributes: channel-group auto mode on mac-pinning evaluated config attributes: channel-group auto mode on mac-pinning assigned interfaces: switch(config-port-prof)# copy running-config startup-config
You can manually configure port channel subgroups to manage the traffic flow on multiple upstream switches. This action is required for a port channel that connects to multiple upstream switches where CDP is not configured.
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# interface ethernet range | Enters interface configuration mode for the specified interface range. |
Step 3 | switch(config-if)# sub-group id number | Manually configures a subgroup to manage traffic for the upstream switch. Allowable subgroup numbers are from 0 to 31. |
Step 4 | Repeat Step 2 and 3. | Perform this step for each port connected to an upstream switch where CDP is not configured. |
Step 5 | switch(config-if)# show interface ethernet range | (Optional) Displays the configuration for verification. |
Step 6 | switch(config-if)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to manually configure port channel subgroups for a host in module 3 which has four physical ports. The upstream switches do not support CDP. Ethernet ports 3/2 and 3/3 connect to one upstream switch and the Ethernet ports 3/4 and 3/5 connect to another upstream switch.
switch# configure terminal switch(config)# int eth3/2 switch(config-if)# sub-group-id 0 switch(config-if)# int eth3/3 switch(config-if)# sub-group-id 0 switch(config-if)# int eth3/4 switch(config-if)# sub-group-id 1 switch(config-if)# int eth3/5 switch(config-if)# sub-group-id 1 switch(config-if)# copy running-config interface . . . interface Ethernet3/2 inherit port-profile system-uplink-pvlan sub-group-id 0 interface Ethernet3/3 inherit port-profile system-uplink-pvlan sub-group-id 0 interface Ethernet3/4 inherit port-profile system-uplink-pvlan sub-group-id 1 interface Ethernet3/5 inherit port-profile system-uplink-pvlan sub-group-id 1 switch(config-if)#
You can pin a vEthernet interface to a specific port channel subgroup in the port profile configuration.
Note |
You can also pin a subgroup to a vEthernet interface in the interface configuration. See Configuring Static Pinning for an Interface. |
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# port-profile type vethernet name | Enters port profile configuration mode for the named port profile. |
Step 3 | switch(config-port-prof)# pinning id subgroup_id [ backup subgroup_id1...subgroup_id7 ] | For the named port profile, assigns (or pins) a vEthernet interface to a port channel subgroup (0–31) backup—To optionally specify an ordered list of backup subgroups for pinning to be used if the primary subgroup is not available. |
Step 4 | switch(config-port-prof)# show port-profile [brief | expand-interface | usage] [name profile-name] | (Optional) Displays the configuration for verification. |
Step 5 | switch(config-port-prof)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to create a vEthernet port profile and pin it to port channel subgroup 3:
switch# configure terminal switch(config)# port-profile type vethernet PortProfile1 switch(config-port-prof)# pinning id 3 switch(config-port-prof)# show port-profile name PortProfile1 port-profile PortProfile1 description: type: vethernet status: disabled capability l3control: no pinning control-vlan: - pinning packet-vlan: - system vlans: none port-group: max ports: 32 inherit: config attributes: pinning id 3 evaluated config attributes: pinning id 3 assigned interfaces: switch(config-port-prof)# copy running-config startup-config
This example shows how to create a vEthernet port profile and pin it to port channel subgroup 3 and backup subgroups 4 and 6:
switch# configure terminal switch(config)# port-profile type vethernet PortProfile1 switch(config-port-prof)# pinning id 3 backup 4 6 switch(config-port-prof)# show port-profile name PortProfile1 port-profile PortProfile1 description: type: vethernet status: disabled capability l3control: no pinning control-vlan: - pinning packet-vlan: - system vlans: none port-group: max ports: 32 inherit: config attributes: pinning id 3 backup 4 6 evaluated config attributes: pinning id 3 assigned interfaces: switch(config-port-prof)# copy running-config startup-config
You can pin a control or packet VLAN to a specific subgroup.
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# port-profile name | Enters port profile configuration mode for the named port profile. |
Step 3 | switch(config-port-prof)# pinning {control-vlan | packet-vlan} subgroup_id | Assigns (or pins) a control VLAN or packet VLAN to a port channel subgroup (0 to 31). |
Step 4 | switch(config-port-prof)# show port-profile [brief | expand-interface | usage] [name profile-name] | (Optional) Displays the configuration for verification. |
Step 5 | switch(config-port-prof)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to configure static pinning on a control VLAN:
switch# configure terminal switch(config)# port-profile SystemProfile1 switch(config-port-prof)# pinning control-vlan 3 switch(config-port-prof)# show port-profile SystemProfile1 port-profile SystemProfile1 description: type: ethernet status: disabled capability l3control: no pinning control-vlan: 3 pinning packet-vlan: - system vlans: 1 port-group: SystemProfile1 max ports: - inherit: config attributes: switchport mode trunk switchport trunk allowed vlan 1-5 no shutdown evaluated config attributes: switchport mode trunk switchport trunk allowed vlan 1-5 no shutdown assigned interfaces: switch(config-port-prof)# copy running-config startup-config
This example shows how to configure static pinning on a packet VLAN:
switch# configure terminal switch(config)# port-profile SystemProfile1 switch(config-port-prof)# pinning packet-vlan 0 switch(config-port-prof)# show port-profile name SystemProfile1 port-profile SystemProfile1 description: type: ethernet status: disabled capability l3control: no pinning control-vlan: - pinning packet-vlan: 0 system vlans: 1 port-group: max ports: - inherit: config attributes: switchport mode access switchport access vlan 1 switchport trunk native vlan 1 no shutdown evaluated config attributes: switchport mode access switchport access vlan 1 switchport trunk native vlan 1 no shutdown assigned interfaces: switch(config-port-prof)# copy running-config startup-config
You can migrate a channel group to a port profile.
Log in to the CLI in EXEC mode.
Step 1 | Place the host in maintenance mode. | ||
Step 2 |
Do one of the following:
|
||
Step 3 |
When all the virtual machines are successfully migrated, from the Cisco Nexus 1000V CLI, create a new Ethernet type port profile for the uplink ports on this host.
|
||
Step 4 |
Remove the port channel configuration from the uplink switches.
|
||
Step 5 | When all the port(s) are moved from the old port profile, use the following command from the Cisco Nexus 1000V CLI to delete the port channels with zero members:no interface port-channel id | ||
Step 6 | Bring the host out of maintenance mode. | ||
Step 7 |
To save the running configuration persistently through reboots and restarts by copying it to the startup configuration, enter the following command: copy running-config startup-config |
||
Step 8 | Create the port channel type in the upstream switch. See Creating a Port Profile for a Port Channel. |
To move port profile types in a port profile, you tear down the existing port channel then recreate the port channel.
Log in to the CLI in EXEC mode.
Step 1 | Place the host in maintenance mode. |
Step 2 |
Do one of the following:
|
Step 3 |
When all the virtual machines are successfully migrated, from the Cisco Nexus 1000V CLI, create a new Ethernet type port profile for the uplink ports on this host.
|
Step 4 | Remove the port channel that you want to migrate in the upstream switch. See Removing a Port Channel Group from a Port Profile. |
Step 5 | Remove the port channel in the upstream switch. |
Step 6 | Manually configure subgroup IDs in the Cisco Nexus 1000V Ethernet interface. See Manually Configuring Interface Subgroups |
Step 7 | Change the port channel type in the Cisco Nexus 1000V port profile. See Migrating a Channel Group to a Port Profile |
Step 8 | Change the port channel type in the Cisco Nexus 1000V port profile. See Connecting to a Single Upstream Switch |
Step 9 | Bring the host out of maintenance mode. |
Step 10 | Migrate the virtual machines back to this host. |
Step 11 |
To save the running configuration persistently through reboots and restarts by copying it to the startup configuration by entering the following command: copy running-config startup-config |
Step 12 | Create the port channel type that you want in the upstream switch. See Creating a Port Profile for a Port Channel. |
You can configure Network State Tracking to pinpoint link failures on port channels configured for vPC-HM.
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# track network-state enable | Enables Network State Tracking on all interfaces in vPC-HM port-channels. |
Step 3 | switch(config)# track network-state interval seconds | (Optional) Specifies the interval of time, from 1 to 10 seconds, between which tracking broadcasts are sent; and the interval for tracking packets. The default interval is 5 seconds between broadcasts. |
Step 4 | switch(config)# track network-state split action [repin | log-only] | (Optional) Specifies the action to be taken if a split network is detected. |
Step 5 | switch(config)# track network-state threshold miss-count count | (Optional) Specifies the maximum number of broadcasts that can be missed successively (from 3 to 7) before a split network is declared. The default is 5 missed broadcasts. |
Step 6 | switch(config)# show network-state tracking config | (Optional) Displays the Network State Tracking configuration for verification. |
Step 7 | switch(config-if)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to configure Network State Tracking with an 8 second interval between each sent broadcast, repinning traffic to another uplink if a split network is detected, and a maximum of 7 missed broadcasts before declaring a split network:
switch# configure terminal switch(config)# track network-state enable switch(config)# track network-state interval 8 switch(config)# track network-state split action repin switch(config)# track network-state threshold miss-count 7 switch(config)# show network-state tracking config Tracking mode : enabled Tracking Interval : 8 sec Miss count threshold : 7 pkts Split-network action : repin switch(config)#
You can configure static pinning on a vEthernet interface.
Note |
You can also pin a subgroup to a vEthernet interface in the port profile configuration. See Pinning a vEthernet Interface to a Subgroup. |
Log in to the CLI in EXEC mode.
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# interface vethernet interface-number | Enters interface configuration mode for the specified interface (from 1 to 1048575). |
Step 3 | switch(config-if)# pinning id subgroup_id [ backup subgroup_id1...subgroup_id7 ] | Assigns (or pins) a vEthernet interface to a specific port channel subgroup (from 0 to 31). backup—To optionally specify an ordered list of backup subgroups for pinning to be used if the primary subgroup is not available. |
Step 4 | switch(config-if)# show running-config interface vethernet interface-number | (Optional) Displays the pinning configuration of the specified interface. |
Step 5 | switch(config-if)# module vem module_number execute vemcmd show pinning | (Optional) Displays the pinning configuration on the specified VEM. |
Step 6 | switch(config-if)# module vem module_number execute vemcmd show static pinning config | (Optional) Displays the VSM configured pinning subgroups. |
Step 7 | switch(config-if)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to pin subgroup ID 0 to vEthernet interface 1:
switch# configure terminal switch(config)# interface vethernet 1 switch(config-if)# pinning id 0 switch(config-if)# show running-config interface vethernet 1 version 4.0(4)SV1(2) interface Vethernet3 service-policy type qos input policy1 pinning id 0 switch(config-if)# exit switch(config)# exit switch# module vem 3 execute vemcmd show pinning LTL IfIndex PC_LTL VSM_SGID VEM_SGID Eff_SGID 48 1b040000 304 0 0 0 switch#
The following example shows the output after configuring backup subgroups for pinning:
switch(config-if)# module vem 4 execute vemcmd show static pinning config LTL IfIndex VSM_SGID Backup_SGID 48 1c0000a0 0, 1,2 50 1c000100 0, 1 switch(config-if)# copy running-config startup-config
You can remove a port channel group from a port profile.
You are logged in to the CLI in EXEC mode.
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# port-profile name | Specifies the port profile from which the port channel will be removed. |
Step 3 | switch(config-port-prof)# no channel-group auto | Removes the channel group configuration from all member interfaces in the specified port profile. |
Step 4 | switch(config-port-prof)# show port-profile name | (Optional) Displays the configuration for verification. |
Step 5 | switch(config-port-prof)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to remove a port channel group from a port profile:
switch# configure terminal switch(config)# port-profile testProf switch(config-port-prof)# no channel-group auto switch(config-port-prof)# show port-profile testProf switch(config-port-prof)#
You can shut down and restart a port channel interface.
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# interface port-channel channel-number | Enters interface configuration mode for the specified port channel interface. |
Step 3 | switch(config-if)# shutdown | no shutdown | The shutdownkeyword shuts down the interface. No traffic passes and the interface displays as administratively down. The default is no shutdown. Brings the interface back up. The interface displays as administratively up. If there are no operational problems, traffic passes. The default is no shutdown. |
Step 4 | switch(config-if)# show interface port-channel channel-number | (Optional) Displays interface information for the specified port channel. |
Step 5 | switch(config-if)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This following example shows how to bring up the interface for port channel 2:
switch# configure terminal switch(config)# interface port-channel 2 switch(config-if)# no shutdown
You can add a description to a port channel interface.
Log in to the CLI in EXEC mode.
Command or Action | Purpose | |||
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Step 1 | switch# configure terminal | Enters global configuration mode. |
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Step 2 | switch(config)# interface port-channel channel-number | Places you into interface configuration mode for the specified port channel interface. For the channel number, the range is from 1 to 4096. The port channel associated with this channel group is automatically created if the port channel does not already exist. |
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Step 3 | switch(config-if)# description string | Adds a description to the port channel interface. For string, the description can be up to 80 alphanumeric characters.
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Step 4 | switch(config-if)# show interface port-channel channel-number | (Optional) Displays interface information for the specified port channel. |
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Step 5 | switch(config-if)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to add a description to port channel 2:
switch# configure terminal switch(config)# interface port-channel 2 switch(config-if)# description engineering
You can configure port channel load balancing.
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# port-channel load-balance ethernet {dest-ip-port | dest-ip-port-vlan | destination-ip-vlan | destination-mac | destination-port | source-dest-ip-port | source-dest-ip-port-vlan | source-dest-ip-vlan | source-dest-mac | source-dest-port | source-ip-port | source-ip-port-vlan | source-ip-vlan | source-mac | source-port | source-virtual-port-id | vlan-only } | Configures the load balance method for the device or module. The range depends on the device. The default load balancing method uses the source MAC address. |
Step 3 | switch(config)# show interface port-channel load balance | (Optional) Displays the port channel load-balancing method. |
Step 4 | switch(config)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to configure the source IP load-balancing method for port channels on module 5:
switch# configure terminal switch# interface port channel 2 switch# port-channel load-balance ethernet source-ip module 5
You can configure the speed and duplex settings for a port channel interface.
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# interface port-channel channel-number | Specifies the port channel interface that you want to configure and enters the interface mode. Allowable channel numbers are from 1 to 4096. |
Step 3 | switch(config-if)# speed {10 | 100 | 1000 | auto} | Sets the speed for the port channel interface. The default is auto for autonegotiation. |
Step 4 | switch(config-if)# duplex {auto | full | half} | Sets the duplex mode for the port channel interface. The default is auto for autonegotiation. |
Step 5 | switch(config-if)# show interface port-channel channel-number | (Optional) Displays interface information for the specified port channel. |
Step 6 | switch(config-if)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to set port channel 2 to 100 Mbps:
switch# configure terminal switch(config)# interface port channel 2 switch(config-if)# speed 100
You can restore the default load-balancing method.
Log in to the CLI in EXEC mode.
Command or Action | Purpose | |
---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
Step 2 | switch(config)# no port-channel load-balance ethernet | Restores the default load-balancing method, which is the source MAC address. |
Step 3 | switch(config)# show interface port-channel load balance | (Optional) Displays the port channel load-balancing method. |
Step 4 | switch(config)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to restore the default load-balancing method:
switch# configure terminal switch(config)# no port-channel load-balance ethernet switch(config)# show port-channel load-balance
You can configure the following requirements for LACP:
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
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Step 2 | switch(config)# feature lacp | Enables LACP support for port channels. |
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Step 3 | switch(config-if)# port-profile [ type {ethernet | vethernet}] name | Enters port profile configuration mode for the named port profile.
For configuring port channels, specify the port profile as an Ethernet type. Defining a port profile as an Ethernet type allows the port profile to be used for physical (Ethernet) ports. In the vCenter Server, the corresponding port group can be selected and assigned to physical ports (PNICs).
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Step 4 | switch(config-port-prof)# vmware port-group [pg_name] | Designates the port profile as a VMware port group. The port profile is mapped to a VMware port group of the same name unless you specify a name here. When you connect the VSM to vCenter Server, the port group is distributed to the virtual switch on the vCenter Server. |
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Step 5 | switch(config-port-prof)# switchport mode {access | private-vlan {host | promiscuous} | trunk} | Designates how the interfaces are to be used. Allowable port modes: A trunk port transmits untagged packets for the native VLAN and transmits encapsulated, tagged packets for all other VLANs. |
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Step 6 | switch(config-port-prof)# switchport trunk allowed vlan vlan-id-list | Designates the port profile as trunking and defines VLAN access to it as follows:
If you do not configure allowed VLANs, the default VLAN 1 is used as the allowed VLAN. If you want traffic forwarded on the native VLAN of the trunk port, the native VLAN must be in the allowed VLAN list. |
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Step 7 | switch(config-port-prof)# show port-profile name | (Optional) Displays the configuration for verification. |
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Step 8 | switch(config-port-prof)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
This example shows how to remove a port channel group from a port profile:
switch# configure terminal switch(config)# port-profile testProf switch(config-port-prof)# no channel-group auto switch(config-port-prof)# show port-profile testProf switch(config-port-prof)#
You can offload management of LACP from the VSM to the VEMs.
Note |
If you have upgraded from a previous release, offloading of LACP management to the VEMs is disabled by default. You can enable or disable the feature using the [no] lacp offload command |
Command or Action | Purpose | |||
---|---|---|---|---|
Step 1 | switch# configure terminal | Enters global configuration mode. |
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Step 2 | switch(config)# lacp offload | (Optional) Offloads LACP management from the VSM to the VEMs. If enabling LACP offload, a message displays to let you know that a reload is required. Offload of LACP management to the VEMs is enabled by default.
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Step 3 | switch(config)# copy running-config startup-config | (Optional) Saves the change persistently through reboots and restarts by copying the running configuration to the startup configuration. |
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Step 4 | switch(config)# show lacp offload status | (Optional) Displays the LACP offload status for verification.
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Step 5 | switch(config)# reload | Reboots both the primary and secondary VSM. |
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Step 6 | switch(config)# show lacp offload status | (Optional) Displays the LACP offload status for verification.
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This example shows how to offload management of LACP from the VSM to the VEMs:
switch# configure terminal switch(config)# lacp offload Please do a "copy running startup" to ensure the new setting takes effect on next reboot LACP Offload Status can be verified using "show lacp offload status" Change in LACP Offload Status takes effect only on the next VSM Reboot This can potentially cause modules with LACP uplinks to flap switch(config)# copy running-config startup-config switch(config)# show lacp offload status Current Status : Disabled Running Config Status : Enabled Saved Config Status : Enabled switch(config)# reload This command will reboot the system. (y/n)? [n] y 2010 Sep 3 11:33:35 n1000v %PLATFORM-2-PFM_SYSTEM_RESET: Manual system restart from Command Line Interface n1000v(config)# show lacp offload status Current Status : Enabled Running Config Status : Enabled Saved Config Status : Enabled switch(config)#
Use the following commands to verify the port channel configuration:
Command | Purpose |
---|---|
show feature |
Displays the features available, and whether they are enabled. |
show interface port-channel channel-number |
Displays the status of a port channel interface. |
show lacp port-channel [interface port-channel channel-number ] |
Displays information about LACP port channels. |
show lacp interface ethernet slot/port |
Displays information about specific LACP interfaces. |
show lacp offload status |
Displays whether LACP management is offloaded to the VEMs. |
show network-state tracking config |
Displays the Network State Tracking configuration for verification. |
show network-state tracking { module modID | interface channelID} |
Displays the Network State Tracking status for a module or interface. |
show port-channel compatibility-parameters |
Displays the parameters that must be the same among the member ports in order to join a port channel. |
show port-channel database [ interface port-channel channel-number ] |
Displays the aggregation state for one or more port channel interfaces. |
show port-channel load-balance |
Displays the type of load balancing in use for port channels. |
show port-channel summary |
Displays a summary for the port channel interfaces. |
show port-channel traffic |
Displays the traffic statistics for port channels. |
show port-channel usage |
Displays the range of used and unused channel numbers. |
show running-config interface ethernet port/slot |
Displays information about the running configuration of the specified Ethernet interface. |
show running-config interface port-channel channel-number |
Displays information about the running configuration of the port channel. |
show running-config interface vethernet interface-number |
Displays information about the running configuration of the specified vEthernet interface. |
Use the following commands to monitor the port channel interface configuration:
Command | Purpose |
---|---|
clear counters interface port-channel channel-number |
Clears the counters. |
show interface counters [ module module ] |
Displays input and output octets unicast packets, multicast packets, and broadcast packets. |
show interface counters detailed [ all ] |
Displays input packets, bytes, and multicast and output packets and bytes. |
show interface counters errors [ module module ] |
Displays information on the number of error packets. |
show lacp counters [ interface port-channel channel-number ] |
Displays information about LACP statistics. |
This example shows how to create a port channel and add two Layer 2 interfaces to that port channel:
switch# configure terminal switch(config)# interface port-channel 5 switch(config-if)# interface ethernet 1/4 switch(config-if)# switchport switch(config-if)# channel-group 5 mode active switch(config-if)# interface ethernet 1/7 switch(config-if)# switchport switch(config-if)# channel-group 5 mode switch(config-if)#
This example shows how to set the LACP-enabled interface to the active port channel mode for Ethernet interface 1/4 in channel group 5 and then configure an LACP port profile for the port channel:
switch# configure terminal switch(config)# feature lacp switch(config)# interface ethernet 1/4 switch(config-if)# channel-group 5 mode active switch(config-if)# port-profile type ethernet system-uplink switch(config-port-prof)# vmware port-group lacp switch(config-port-prof)# switchport mode trunk switch(config-port-prof)# switchport trunk allowed vlan 1-100 switch(config-port-prof)# channel-group auto mode active switch(config-port-prof)# system vlan 1,10,20 switch(config-port-prof)# state enabled switch(config-port-prof)# show port-channel summary switch(config-port-prof)# copy running-config startup-config
This example shows how to configure Network State Tracking with an 8-second interval between sent broadcasts, with a maximum of 7 missed broadcasts before declaring a split network, and how to repin traffic to another uplink if a split network is detected:
switch# configure terminal switch(config)# track network-state enable switch(config)# track network-state interval 8 switch(config)# track network-state split action repin switch(config)# track network-state threshold miss-count 7 switch(config)# show network-state tracking config Tracking mode : enabled Tracking Interval : 8 sec Miss count threshold : 7 pkts Split-network action : repin switch(config)#
Feature Name |
Releases |
Feature Information |
---|---|---|
Backup subgroups |
4.2(1)SV1(4a) |
You can assign up to seven backup subgroups when pinning the primary subgroup. |
Port channel relative numbering |
4.2(1)SV1(4a) |
The subgroup numbering begins at zero and is not tied to the vmnic number. |
Port channel vPC-HM |
4.2(1)SV1(4) |
The interface sub-group cdp command is removed from the port channel vPC-HM configuration when connecting to multiple upstream switches. |
Network State Tracking for vPC-HM port channels |
4.2(1)SV1(4) |
Pinpoints link failure on a port channel configured for vPC-HM. |
VEM management of LACP |
4.2(1)SV1(4) |
Offloading management of LACP from the VSM to the VEMs. |
Enabling the LACP port channel function |
4.2(1)SV1(4) |
The feature lacp command, is added to enable support of LACP port channels. Previously LACP was enabled automatically. |
vPC-Host Mode |
4.0(4)SV1(2) |
Support for manual creation of subgroups. |
Static Pinning |
4.0(4)SV1(2) |
Support for attaching (or pinning) a vEthernet interface to a specific port channel subgroup. |
Port Channels |
4.0(4)SV1(1) |
This feature was introduced. |