Contents
- Configuring Adapter-FEX
- Adding a Server with a Server Network Adapter
- Enabling Switch for Adapter-FEX
- Configuring the Adapter FEX Feature
- Configuring a Server Network Adapter
- Server Network Adapter Initial Handshake and Negotiation
- Configuring vNICs on Server Network Adapter
- Initializing the Server Network Adapter
- Cisco Nexus Adapter FEX Initialization Example for a Dual-Homed FEX Topology
- Cisco Nexus Adapter-FEX Initialization Example with Active-Standby Topology
- Cisco Nexus Adapter FEX Initialization Example for a Dual-Homed FEX with Active-Standby Topology
- Creating Vethernet Interfaces
- Saving Vethernet Interfaces in the Startup-config
- Configuring Vethernet Interfaces Manually
- Configuration Conflicts Between Switch and Server Network Adapter
- Configuration Conflicts Between Switches
- Removing a Server with a Server Network Adapter
- Relocating a Server to a Different Physical Interface
- Adding or Deleting Port-Profiles
- Disabling Adapter-FEX on a Switch
Configuring Adapter-FEX
The chapter contains the following sections:
- Adding a Server with a Server Network Adapter
- Removing a Server with a Server Network Adapter
- Disabling Adapter-FEX on a Switch
Adding a Server with a Server Network Adapter
The following sections describe how to configure a server with a server network adapter for Adapter-FEX.
Enabling Switch for Adapter-FEX
Enable the Adapter-FEX feature on each of the switches that the server is connecting to.
1.
configure terminal
2.
install feature-set virtualization
3.
feature-set virtualization
4.
vethernet auto-create
DETAILED STEPS
Example:
switch# configure terminal switch(config)# install feature-set virtualization switch(config)# feature-set virtualization switch(config)# vethernet auto-create switch(config)#
Configuring the Adapter FEX Feature
Configure the switch to support Adapter-FEX.
Enable the Adapter FEX feature by enabling the virtualization feature set.
Enable network interface virtualization (NIV) on the physical server adapters using the Cisco Integrated Management Controller (CIMC).
1. switch# configure terminal
2. switch(config)#port-profile type vethernet port-profile_name
3. switch(config-port-profile)#state enabled
4. switch(config-port-profile)#exit
5. switch(config)#interface ethernet type /port
6. switch(config-if)#switchport mode vntag
7. switch(config-if)#exit
8. (Optional) switch(config-if)# copy running-config startup-config
9. Connect the server network adapter uplinks.
DETAILED STEPS
The following example show how to configure a Cisco Nexus switch with four vNICs by creating one port-profile for each type of vNIC:
switch# configure terminal
switch(config)# port-profile type vethernet user_data1
switchport trunk allowed vlan 2-100
switchport trunk native vlan 2
switchport mode trunk
switch(config)# state enabled
switch(config)# port-profile type vethernet user_data2
switchport trunk allowed vlan 2-100
switchport trunk native vlan 2
switchport mode trunk
switch(config)# state enabled
switch(config)# port-profile type vethernet user_management
switchport access vlan 1
switch(config)# state enabled
switch(config)# port-profile type vethernet user_backup
switchport mode trunk
switchport trunk allowed vlan 2-100
switchport trunk native vlan 2
mac port access-group mac_acl1
ip port access-group ip_acl1 in
ipv6 port traffic-filter ipv6_acl1 in
switch(config)# state enabled
switch(config)# interface ethernet1/5
description ucs_vic2/0
switch(config-if)# switchport mode vntag
switch(config-if)#
Configuring a Server Network Adapter
Using the network adapter configuration utility on the server, enable Network Interface Virtualization (NIV) mode on the network adapter. See the documentation of your specific server network adapter for details. To complete the configuration, you might have to reboot the server to reset the network adapter.
Server Network Adapter Initial Handshake and Negotiation
When connecting the server network adapter to the enabled VNTag mode Ethernet port on a switch or to a FEX, a handshake is initiated. An exchange of information about NIV capabilities takes place and communications begin in VNTag mode. The switch passes the list of configured port-profiles (type vethernet) down to the adapter. These port-profile names are displayed in the server network adapter’s configuration utility as options for selection.
Only port-profile names are passed to the server network adapter. The configurations in the port-profile are not passed to the server network adapter.
If the server network adapter is not connected to the switch, it is still possible to configure the virtual network interface cards (vNICs) on the server. However the port-profile names are not available on the adapter.
Configuring vNICs on Server Network Adapter
Using the network adapter configuration utility on the server, create the appropriate number of vNICs. Create each vNIC with the appropriate properties, such as unique channel number, MAC address, uplink failover properties, or port-profile names.
 Note | After the initial handshake and negotiation, the list of port-profiles configured on the switch are automatically available on the server adapter. You can associate these port-profile names to the vNICs. |
Each vNIC has a unique channel number associated with it. A vNIC is identified on the switch by the bind command that associates a physical port and the vNIC’s channel number to a vethernet interface. Refer to the documentation of your specific server network adapter for details.
For the Broadcom BCM57810 Convergence Network Interface Card, refer to your source for Broadcom Corp. documentation.
When VNtag connectivity is established, only port-profile names (type vethernet) are passed to the server network adapter. The configurations in the port-profile are not passed to the server network adapter.
The port-profiles names are displayed in the server network adapter’s configuration utility as options for selection.
Initializing the Server Network Adapter
After you configure the vNICs on the server network adapter, you might have to consider the following to complete the configuration.
See the documentation for your specific server network adapter for details.
When the configuration is complete, the server network adapter and the switch re-establishes a link and performs the initial handshake and negotiation process. The server network adapter and the switch also establish higher level control plane connectivity using the Virtual Interface Configuration (VIC) protocol.
Note | The VIC protocol allows you to provision and manage virtual interfaces on a remote device. |
When the VIC protocol connectivity is established, the server network adapter requests that the switch create a Vethernet interface for each vNIC that is configured on the server network adapter. The server network adapter also passes the following attributes over the uplink in addition to the create Vethernet interface request:
The switch responds by creating a Vethernet interface for each vNIC on the server network adapter and associates the port-profile and channel number to the Vethernet interface.
The server bootup process might be held at the BIOS configuration phase until the Vethernet creation has completed. After the Vethernet is created, the bootup process resumes and the operating system is loaded. See to the documentation for your specific adapter for details.
The global configuration command, no vethernet auto-create, stops the Vethernet interfaces from being automatically created. If the switch is not configured with the vethernet auto-create command, you must configure the Vethernet interfaces manually with the appropriate binding and port-profile configurations.
Vethernet interfaces created by the switch are numbered automatically as they are created. These vethernet numbers start from 32769. The switch picks the lowest unused number when creating a Vethernet interface.
When you manually create Vetethernet interfaces, you may select any number for the Vethernet. However, as a best practice, you should choose a number that is less that 32678.
Example of configuring Vethernet interfaces
switch# interface vethernet 21
bind interface ethernet 1/5 channel 1
inherit port-profile user_data
switch# interface vethernet 22
bind interface ethernet 1/5 channel 2
inherit port-profile user_data
switch# interface vethernet 23
bind interface ethernet 1/5 channel 3
inherit port-profile user_management
switch# interface vethernet 24
bind interface ethernet 1/5 channel 4
inherit port-profile user_backup
Cisco Nexus Adapter FEX Initialization Example for a Dual-Homed FEX Topology
The following figure shows a topology with a dual-homed FEX.
Vethernet interface initialization results of the Cisco Nexus Swtich-A
switch# interface vethernet 21
bind interface ethernet 101/1/15 channel 1
inherit port-profile user_data
switch# interface vethernet 22
bind interface ethernet 101/1/15 channel 2
inherit port-profile user_data
switch# interface vethernet 23
bind interface ethernet 101/1/15 channel 3
inherit port-profile user_management
switch# interface vethernet 24
bind interface ethernet 101/1/15 channel 4
inherit port-profile user_backup
switch# interface vethernet 21
bind interface ethernet 101/1/15 channel 1
inherit port-profile user_data
switch# interface vethernet 22
bind interface ethernet 101/1/15 channel 2
inherit port-profile user_data
switch# interface vethernet 23
bind interface ethernet 101/1/15 channel 3
inherit port-profile user_management
switch# interface vethernet 24
bind interface ethernet 101/1/15 channel 4
inherit port-profile user_backup
Note | The initialization results are identical for both switches. |
Cisco Nexus Adapter-FEX Initialization Example with Active-Standby Topology
The active-standby topologies described here have one uplink as active and the other uplink as standby. With some server network adapters, you may select the active and standby uplinks per vNIC. In this case, each uplink is an active uplink for a specific vNIC and becomes a standby for the remainder uplinks. For each vNIC, you should choose the active and standby uplinks as a best practice.
Channel numbers for Vethernet interfaces created on the standby uplink device are the same as the channel numbers on the active uplink.
Consider the following figure showing a topology with active-standby uplinks.
In a virtual port channel (vPC) topology, the Vethernet interfaces that are associated with a single vNIC has the same interface number on the vPC primary and secondary switch.
Assume that the server network adapter in this example has four vNICs (eth0, eth1, eth2, eth3) and two uplinks (uplink_0 and uplink_1) with the configuration described in the following table:
vNIC |
Uplink |
Port-profile Name |
Channel Number |
eth0 |
Uplink_0 |
user_data |
1 |
eth1 |
Uplink_1 |
user_management |
2 |
eth2 |
Uplink_0 |
user_data |
3 |
eth3 |
Uplink_1 |
user_backup |
4 |
Also assume that uplink_0 is connected to Ethernet 1/5 on Swtich-A and that uplink_1 is connected to Ethernet 1/15 on Switch-B.
In a vPC active-standby topology, Vethernet numbers are allocated by the vPC primary switch. When a Vethernet create request is received, the vPC secondary switch requests the primary switch for an allocation. The show vpc brief command displays the vPC role of a switch.
If a server is moved from one port to another port on either the primary vPC switch or the secondary vPC switch, the server network adapter connectivity is not established until the old Vethernet interfaces are deleted.
Vethernet interface initialization results of Cisco Nexus Switch-A
switch# interface vethernet 37
bind interface ethernet 1/5 channel 1
inherit port-profile user_data
switch# interface vethernet 38
bind interface ethernet 1/5 channel 2
inherit port-profile user_data
switch# interface vethernet 39
bind interface ethernet 1/5 channel 3
inherit port-profile user_management
switch# interface vethernet 40
bind interface ethernet 1/5 channel 4
inherit port-profile user_backup
switch# interface vethernet 37
bind interface ethernet 1/5 channel 1
inherit port-profile user_data
switch# interface vethernet 38
bind interface ethernet 1/5 channel 2
inherit port-profile user_data
switch# interface vethernet 39
bind interface ethernet 1/5 channel 3
inherit port-profile user_management
switch# interface vethernet 40
bind interface ethernet 1/5 channel 4
inherit port-profile user_backup
Note | The initialization results are identical for both switches. |
Cisco Nexus Adapter FEX Initialization Example for a Dual-Homed FEX with Active-Standby Topology
The following figure shows a topology with active-standby uplinks.
Assume that the adapter in this example has four vNICs (eth0, eth1, eth2, eth3) and two uplinks (uplink_0 and uplink_1) with the configuration described in the following table:
vNIC |
Uplink |
Port-profile Name |
Channel Number |
eth0 |
Uplink_0 |
user_data |
1 |
eth1 |
Uplink_1 |
user_management |
2 |
eth2 |
Uplink_0 |
user_data |
3 |
eth3 |
Uplink_1 |
user_backup |
4 |
Also assume that uplink_0 is connected to Ethernet 100/1/15 on and that uplink_1 is connected to Ethernet 101/1/15.
Vethernet interface initialization results of Cisco Nexus Switch-A
switch# interface vethernet 37
bind interface ethernet 100/1/15 channel 1
bind interface ethernet 101/1/15 channel 1
inherit port-profile user_data
switch# interface vethernet 38
bind interface ethernet 100/1/15 channel 2
bind interface ethernet 101/1/15 channel 2
inherit port-profile user_data
switch# interface vethernet 39
bind interface ethernet 100/1/15 channel 3
bind interface ethernet 101/1/15 channel 3
inherit port-profile user_management
switch# iinterface vethernet 40
bind interface ethernet 100/1/15 channel 4
bind interface ethernet 101/1/15 channel 4
inherit port-profile user_backup
switch# interface vethernet 37
bind interface ethernet 100/1/15 channel 1
bind interface ethernet 101/1/15 channel 1
inherit port-profile user_data
switch# interface vethernet 38
bind interface ethernet 100/1/15 channel 2
bind interface ethernet 101/1/15 channel 2
inherit port-profile user_data
switch# interface vethernet 39
bind interface ethernet 100/1/15 channel 3
bind interface ethernet 101/1/15 channel 3
inherit port-profile user_management
switch# interface vethernet 40
bind interface ethernet 100/1/15 channel 4
bind interface ethernet 101/1/15 channel 4
inherit port-profile user_backup
Note | The initialization results are identical for both switches. |
Creating Vethernet Interfaces
The server network adapter makes requests to the switch to create vethernet interfaces one at a time.
Example of results of creating vethernet interface
switch# show running-config interface Vethernet32773
interface Vethernet32773
inherit port-profile sample
bind interface Ethernet1/20 channel 11
switch# show interface Vethernet32773 detail
vif_index: 29
--------------------------
veth is bound to interface Ethernet1/20 (0x1a013000)
priority: 0
vntag: 52
status: standby
channel id: 11
registered mac info:
vlan 0 - mac 00:00:00:00:00:00
vlan 0 - mac 00:22:bd:d6:5f:4b
vlan 0 - mac ff:ff:ff:ff:ff:ff
Saving Vethernet Interfaces in the Startup-config
Vethernet interfaces that are created with a request to create the VIC protocol interface are kept in the running-configuration. When the running-configuration is saved, the Vethernet interfaces and their configurations are saved in the startup-config.
When the switch is reloaded, the switch loads the startup-config and the Vethernet interface is created statically from the startup-config. When the VNTag interface is initialized and the server network adapter makes a request for Vethernet creation, the already existing Vethernet interface is used.
Note | You can delete a Vethernet interface from the system with the no interface vethernet veth-id command. Since vethernet interfaces are saved in the startup-config, a best practice is to save the running-config to the startup-config. |
Configuring Vethernet Interfaces Manually
When a server network adapter is connected to a VNTag-mode Ethernet interface on a switch, the Vethernet interfaces are created automatically. However, Vethernet interfaces can also be created manually from the configuration mode with the interface vethernet veth-id command.
Note | When manually configuring Vethernet interfaces, use the no vethernet auto-create command to disable the automatic creation of Vethernet interfaces. |
When a server network adapter is connected and a request to create a Vethernet is received, the switch checks for a manually configured Vethernet interface that matches the channel number of the Vethernet creation request. If the manually configured Vethernet interface already exists, the manually configured Vethernet interface is used and a new Vethernet interface is not created.
Configuration Conflicts Between Switch and Server Network Adapter
Conflicts with port-profile names might occur between the configuration of a Vethernet interface that was manually configured or one that was saved in the start-up config and the configuration on the server network adapter.
For example, the server network adapter might associate the vNIC with channel number 5 to the port-profile user_backup, but the switch might associate the Vethernet interface bound to channel number 5 to the port-profile user_data.
When a conflict of this kind occurs, the configuration from the server network adapter takes precedence and overwrites the configuration on the switch.
Note | When a port-profile is associated to a vNIC, but the port-profile does not exist on the switch, the Vethernet creation and initialization fails. |
Configuration Conflicts Between Switches
In a vPC topology, the configuration of a specific Vethernet interface must be identical on both the switches. If there is a mismatch in the configurations on the switches, the resulting configuration conflict causes the Vethernet interfaces to fail.
When a conflict of this kind occurs, you must resolve the conflict manually before the Vethernet interface can be brought up successfully.
Removing a Server with a Server Network Adapter
When a server network adapter is connected to a switch, Vethernet interfaces are created to support the server network adapter. When you want to remove a server network adapter from the topology, disconnecting or powering down the server does not remove these Vethernet interfaces. Stale Vethernet interfaces exist until they are manually deleted.
When the stale Vethernet interfaces are manually deleted, the server that is connected to the server network adapter can be removed from the topology.
Note | As a best practice, you should delete unused Vethernet interfaces to conserve switch resources. |
1.
configure terminal
2.
no interface vethernet veth-id
3.
(Optional) copy running-config startup-config
DETAILED STEPS
Example of removing Vethernet interfaces
switch# configure terminal switch(config)# no interface vethernet 1 switch(config)# copy running-config startup-config switch(config)#
Relocating a Server to a Different Physical Interface
When a server network adapter is relocated from one physical interface on a switch to another identical switch, new Vethernet interfaces are created and are bound to the new physical interface. The original Vethernet interfaces that were bound to the original physical interfaces exist until they are deleted.
When a new server is connected to the physical interface where the original server was connected, the Vethernet interfaces are reused (assuming that the Vethernet interfaces were not deleted). However, this action might cause a conflict between the configuration on the switch and the configuration on the server network adapter.
Note | When a server network adapter is moved from one server to another, the server network adapter configuration, such as the information about vNICs, moves with the server network adapter. The configuration is saved on the server network adapter. |
In a vPC topology, Vethernet numbers for a vNIC must be identical on both vPC peers. Moving a server that has a server network adapter from one physical interface to another for one of the vPC peers without first deleting the Vethernet interfaces on that switch, results in new Vethernet interfaces with different numbers. This results in having the two vPC peers to be not synchronized. Vethernet creation failure occurs when the vPC peers are not synchronized. As a best practice, the original Vethernet interfaces should be deleted before the server is connected to the new physical interface.
1.
shutdown
2.
configure terminal
3.
no interface vethernet veth-id
4.
no switchport mode vntag
5. Unplug the server from both vPC switches.
6. Connect the server to the new physical interface.
7. Configure the server network adapter.
DETAILED STEPS
Example:
Perform the following commands:
switch# shutdown switch# configure terminal switch(config)# no interface vethernet 21 switch(config-if)# no switchport mode vntag switch(config-if)#
Unplug the server from both vPC switches.
Connect the server to the new physical interface.
Configure the server network adapter.
Adding or Deleting Port-Profiles
When a new port-profile of type vethernet is added, it is immediately passed to all connected server network adapters and becomes available. Similarly, when a port-profile is removed, its name is withdrawn from every connected server network adapter.
Note | Because only port-profile names are passed to the server network adapter, changing the configuration within a port-profile does not trigger any information to be passed to the server network adapter. |
Note | When a newly added port-profile is used, such as being associated with an existing or new vNIC, you might need to reboot the server to reset the server network adapter. See the documentation for the your specific adapter for details. |
When a port-profile is deleted, all Vethernet interfaces that are associated with it are brought down.
Disabling Adapter-FEX on a Switch
Disable the Adapter-FEX feature on each of the switches that the server is connected to.
1.
configure terminal
2.
no interface vethernet veth-id
3.
no port-profile type vethernet port-profile_name
4.
no switchport mode vntag
5.
no feature-set virtualization
DETAILED STEPS
Example:
switch# configure terminal switch(config)# no interface vethernet 21 switch(config-if)# no port-profile type vethernet user_data switch(config-if)# no switchport mode vntag switch(config-if)# no feature-set virtualization switch(config-if)#