Cisco CSR 1000V Series Cloud Services Router Software Configuration Guide
Mapping Cisco CSR 1000V Network Interfaces to VM Network Interfaces
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Table of Contents

Mapping Cisco CSR 1000V Network Interfaces to VM Network Interfaces

Mapping the Router Network Interfaces to Virtual Network Interface Cards

Adding and Deleting Network Interfaces on the Cisco CSR 1000V

Cisco CSR 1000V Network Interfaces and VM Cloning

Mapping Cisco CSR 1000V Network Interfaces with vSwitch Interfaces

Mapping the Router Network Interfaces to Virtual Network Interface Cards

The Cisco CSR 1000V maps the GigabitEthernet network interfaces to the logical virtual network interface card (vNIC) name assigned by the VM. The VM in turn maps the logical vNIC name to a physical MAC address.

When the Cisco CSR 1000V is booted for the first time, the router interfaces are mapped to the logical vNIC interfaces that were added when the VM was created. Figure 11-1 shows the relationship between the vNICs and the Cisco CSR 1000V router interfaces.


Note In Cisco IOS XE Release 3.10S and earlier, the first vNIC added is automatically mapped to the GigabitEthernet0 management interface. All subsequent vNICs added are mapped to router interfaces. Support for the GigabitEthernet0 interface was removed in Cisco IOS XE Release 3.11S.


Figure 11-1 vNICs Mapped to Cisco CSR 1000V Router Interfaces

 

 

After the Cisco CSR 1000V boots, you need to display the mapping between the logical interface on the router with the vNIC and the vNIC MAC address using the show platform software vnic-if interface-mapping command. The display for this command is different depending on your Cisco IOS XE release version. The following is a sample display for Cisco IOS XE Release 3.9S:

Router# show platform software vnic-if interface-mapping
--------------------------------------------------------------------------
Interface Name Short Name vNIC Name Mac Addr
--------------------------------------------------------------------------
GigabitEthernet0 Gi0 eth0 (vmxnet3) 000c.2946.3f4d
GigabitEthernet2 Gi2 eth2 (vmxnet3) 0050.5689.0034
GigabitEthernet1 Gi1 eth1 (vmxnet3) 0050.5689.000b
--------------------------------------------------------------------------

Note The vNIC name shown in the display is a logical interface that the Cisco CSR 1000V uses to map to the interface on the hypervisor. It does not always map to the corresponding NIC name added during the VM installation. For example, the logical “eth1” vNIC name in the display may not necessarily map to “NIC1” as added in the VM installation process.


The following is a sample display for Cisco IOS XE Release 3.10S:

Router# show platform software vnic-if interface-mapping
-----------------------------------------------------------------------
Interface Name Driver Name Mac Addr
-----------------------------------------------------------------------
GigabitEthernet0 vmxnet3 000c.2946.3f4d
GigabitEthernet2 vmxnet3 0050.5689.0034
GigabitEthernet1 vmxnet3 0050.5689.000b
-----------------------------------------------------------------------
 

Note that beginning with Cisco IOS XE Release 3.11S, the GigabitEthernet0 interface is no longer supported.


Caution It is important that you verify the interface mapping before you begin configuring the Gigabit Ethernet network interfaces on the Cisco CSR 1000V. This ensures that the network interface configuration will apply to the correct physical MAC address interface on the VM host.

If you reboot the router and do not add or delete any vNICs, the interface mapping will remain the same. If you delete vNICs, special care must be taken to ensure that the configuration for the remaining interfaces remains intact. For more information, see the “Adding and Deleting Network Interfaces on the Cisco CSR 1000V” section.

Adding and Deleting Network Interfaces on the Cisco CSR 1000V

The Cisco CSR 1000V maps the router GigabitEthernet interfaces to the logical vNIC name assigned by the VM, which in turn is mapped to a MAC address on the VM host. You can add or delete vNICs on the VM to add or delete GigabitEthernet interfaces on the Cisco CSR 1000V. You can add vNICs while the router is active.

To delete a vNIC from the VM, you must first power down the VM. If you delete any vNICs, the router must be rebooted. For more information about adding and deleting vNICs, see the VMware Documentation .


Caution We recommend using caution before removing any existing vNICs on the Cisco CSR 1000 VM. If you remove a vNIC without first updating the Cisco CSR 1000V network interface configuration, you risk a configuration mismatch when the router reboots. When the router reboots and a vNIC has been removed, the remaining logical vNIC names could get reassigned to different MAC addresses. As a result, the GigabitEthernet network interfaces on the Cisco CSR 1000V could get reassigned to different physical interfaces on the hypervisor.

Before you add or delete network interfaces, first verify the interface-to-vNIC mapping using the show platform software vnic-if interface-mapping command.

csr1000v# show platform software vnic-if interface-mapping
--------------------------------------------------------------------------
Interface Name Driver Name Mac Addr
--------------------------------------------------------------------------
GigabitEthernet3 vmxnet3 000c.2946.3f4d
GigabitEthernet2 vmxnet3 0050.5689.0034
GigabitEthernet1 vmxnet3 0050.5689.000b
GigabitEthernet0 vmxnet3 000c.2946.3f4d
--------------------------------------------------------------------------
 

After adding or deleting network interfaces on the VM, always verify the new interface-to-vNIC mapping before making configuration changes to the network interfaces. The following example shows the interface mapping after a new vNIC has been added.

csr1000v# show platform software vnic-if interface-mapping
--------------------------------------------------------------------------
Interface Name Driver Name Mac Addr
--------------------------------------------------------------------------
GigabitEthernet4 vmxnet3 0010.0d40.37ff
GigabitEthernet3 vmxnet3 000c.2946.3f4d
GigabitEthernet2 vmxnet3 0050.5689.0034
GigabitEthernet1 vmxnet3 0050.5689.000b
GigabitEthernet0 vmxnet3 000c.2946.3f4d
--------------------------------------------------------------------------
 

The updated display shows the new vNIC that maps to the GigabitEthernet4 network interface on the Cisco CSR 1000V.

Cisco CSR 1000V Network Interfaces and VM Cloning

When first installed, the Cisco CSR 1000V creates a database that maps the vNIC name to the MAC address. This database is used to maintain a persistent mapping between the router interfaces and the vNIC-to-MAC address mapping in case vNICs are added or deleted. The interfaces are mapped to the stored Universal Unique Identification (UUID) maintained by VMware.

The mapping between the router network interfaces and the vNICs only applies to the current VM that the Cisco CSR 1000V is installed on. If the VM is cloned, then the stored UUID will not match the current UUID and the interface mapping will not match the router configuration.

To prevent the interface mapping from becoming mis-matched, you need to perform the following steps on the original VM before cloning:


Step 1 Make sure the original VM includes the number of configured vNICs required on the cloned VM before beginning the cloning process.

Step 2 Enter the clear platform software vnic-if-nvtable command on the original VM.

This command clears the persistent interface database on the original VM and updates the interface mapping to the hypervisor.

Step 3 Reboot the Cisco CSR 1000V.

Step 4 On the cloned VM, verify the interface mapping using the show platform software vnic-if interface-mapping command.

Step 5 Configure the router interfaces on the cloned VM accordingly.

If you follow these steps, the router configuration on the cloned VM should match the configuration of the original VM.


 

Mapping Cisco CSR 1000V Network Interfaces with vSwitch Interfaces

You can configure the network interfaces in ESXi in different ways to accommodate the Cisco CSR 1000V interfaces. Figure 11-2 shows an example where each Cisco CSR 1000V router interface is mapped to one host Ethernet interface.

Figure 11-2 Cisco CSR 1000V Interfaces Mapped to Individual ESXi Host Ethernet Interfaces

Figure 11-3 shows an example with multiple Cisco CSR 1000V interfaces sharing one host ESXi Ethernet interface.

Figure 11-3 Cisco CSR 1000V Interfaces Sharing One ESXi Host Ethernet Interface

Figure 11-4 shows one Cisco CSR 1000V interfaces mapped directly to a trunk interface on the vSwitch.

Figure 11-4 Cisco CSR 1000V Interfaces Directly Mapped to vSwitch Trunk