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Virtualization with VMWare Infrastructure 3.0

Networking – VMWARE

Posted by Preetam on March 21, 2007

If you are using VLAN, in the VLAN ID field, enter a number between 1 and 4094. If you use VLAN ID 4095, port group would see traffic on any VLAN. Blade servers have limited number of NIC, it will be likely be necessary to use VLANs to separate traffic for SVC Console,Vmotion,IP Storage and various group of VMs.

IP Storage refers to any form of storage that uses TCP/IP to access SCSI devices

VMKernel TCP/IP networking stack has been extended to include

iSCSI & NFS (Virtual Machine Datastore,ISO files)

and Vmotion

Service Console and VMKernel Services have completely separate TCP/IP Stacks.

When only one service console connection is present, changing service console configuration is not allowed. Using DHCP for SVC Console, DNS server should be able to map SVC Console’s hostname to dynamically generated IP address. Otherwise you can use IP Address which again might change if lease expires, DHCP is supported only when virtual interface is configured and attached to the network where DHCP server resides.

iSCSI also has service console components, so networks that are used to access targets should be reachable by both Service console and VMKernel TCP/IP Stacks. As result, after you create VMKernel port for iSCSI you must create a SVC Console connection on the same vSwitch as the Vmkernel port.

When you select “Use this port group for VMotion” you broadcasting other ESX server to send Vmotion traffic on this network connection.

Uplink adapters default speed is Autonegotiate.

Layer 2 Security policy are promiscuous mode (by default Reject), MAC address change and forged transmits.Layer is data link layer.

Traffic shaping policies are set to each virtual adapter attached to the port group and not the vSwitch as a whole

Load balancing and failover policy allow you to determine how network traffic is distributed between adapters and how to re-route in case of failure of NIC. Outgoing traffic is controlled by this policy and incoming traffic by physical switch.

Use port group with different sets of active adapters in their teaming policy to separate VM into groups. These can use separate adapters as long as all adapters are up.

esxcfg-vswif -l

Provides a list of the service console’s current network interfaces.

Check that vswif0 is present and that the current IP address and Netmask are


esxcfg-vswitch -l

Provides a list of current virtual switch configurations.

Check that the uplink adapter configured for the service console is connected to the

appropriate physical network.

exscfg-nics -l

Provides a list of current network adapters along with their names

Check that the uplink adapter configured for the service console is up and that the

speed and duplex are both correct.

esxcfg-nics -s <speed> <nic>

Changes the speed of a network adapter.

esxcfg-nics -d <duplex> <nic>

Changes the duplex of a network adapter.

esxcfg-vswif -i <new ip address> vswifX

Changes the service console’s IP address.

esxcfg-vswif -n <new netmask> vswifX

Changes the service console’s netmask.

esxcfg-vswitch -U <old vmnic> <service console vswitch>

Removes the NIC for the service console

esxcfg-vswitch -L <new vmnic> <service console vswitch>

Changes the uplink for the service console.

If you encounter long waits when using esxcfg-* commands, it is possible that DNS is misconfigured.

Connection from Virtual network adapters to port group is made by name, any change in the name would cause loss of connection when VMs are rebooted. It won’t affect already running VMs. Best practise is to avoid renaming networks after they are in use.

Networking - VMWARE

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