{"id":96,"date":"2009-05-06T00:01:34","date_gmt":"2009-05-06T07:01:34","guid":{"rendered":"http:\/\/www.vadapt.com\/?p=96"},"modified":"2010-05-27T06:54:03","modified_gmt":"2010-05-27T13:54:03","slug":"vmxnet3","status":"publish","type":"post","link":"http:\/\/iben.users.sonic.net\/wp\/vmxnet3\/","title":{"rendered":"vmxnet3 – features and use information – tips and tricks"},"content":{"rendered":"
vmxnet3 – features and use information – tips and tricks<\/strong><\/div>\n
\u00a0<\/strong>\u00a0<\/div>\n
UPDATED for Windows 2008 Core<\/strong><\/div>\n

Glad to see this has been posted and we can talk about it now… please share your experiences and let us know if these tips work for you and what sort of performance benefits you’ve noticed when using this new driver.<\/p>\n

We’ve been switching our Windows and Linux VMs to use “VMXNET Enhanced” for some time now and see public information on the new VMXNET3 NIC for guests…
\nThis Thread has been started to help with procedures on the conversion of existing machines from older NIC to newer NIC as it is not 100% straightforward and there are some tricks to remove old hardware and change to new hardware. This would be similar in the physical world to changing from a 100 BaseT PCI Card to a GigE card. The old drivers need to be removed, new drivers installed, and IP Addresses moved over. If you just remove the old NIC and install the new one you may end up with a IP Address Conflict error saying the Address you are trying to use is already in use on another Network Interface. The problem is that when you open Device Manager the old NIC is hidden. See below for steps on how to overcome this.
\nQuestion: What is VMXNET3?
\nAnswer: VMXNET3 builds upon VMXNET and Enhanced VMXNET as the third generation paravirtualized virtual networking NIC for guest operating systems.
\nNew VMXNET3 features over previous version of Enhanced VMXNET include:
\n\u2022 MSI\/MSI-X support (subject to guest operating system kernel support)
\n\u2022 Receive Side Scaling (supported in Windows 2008 when explicitly enabled through the device’s Advanced configuration tab)
\n\u2022 IPv6 checksum and TCP Segmentation Offloading (TSO) over IPv6
\n\u2022 VLAN off-loading
\n\u2022 Large TX\/RX ring sizes (configured from within the virtual machine)<\/p>\n

What’s New in vSphere 4.0<\/strong><\/p>\n

http:\/\/communities.vmware.com\/viewwebdoc.jspa?documentID=DOC-9225&communityID=2701<\/a>
\nhttp:\/\/www.vmware.com\/files\/pdf\/VMW_09Q1_WP_vSphereNetworking_P8_R1.pdf<\/a><\/p>\n

From the Cisco document:<\/a>VMware vSphere 4 and Cisco Nexus 1000V Series<\/a><\/strong><\/p>\n

VMware vNetwork module that encompasses the vDS and VMXNET-3 enables inline monitoring and centralized firewall services and maintains the virtualmachine’s network run-time characteristics.<\/p>\n

http:\/\/www.cisco.com\/en\/US\/prod\/collateral\/switches\/ps9441\/ps9902\/solution_overview_c22-529767-00.pdf<\/a><\/p>\n

Tech Notes<\/h1>\n

Flexible shows up in Windows Device Manager as an \u201cVMware
\nAccelerated AMD PCNet Adapter\u201d and Enhanced vmxnet show up as \u201cVMware
\nPCI Ethernet Adapter\u201d.
\nhttp:\/\/kb.vmware.com\/selfservice\/microsites\/search.do?language=en_US&cmd=displayKC&externalId=1001805<\/a>
\nFlexible<\/strong> \u2014 The Flexible network adapter
\nidentifies itself as a Vlance adapter when a virtual machine boots, but
\ninitializes itself and functions as either a Vlance or a vmxnet
\nadapter, depending which driver initializes it. VMware Tools versions
\nrecent enough to know about the Flexible network adapter include the
\nvmxnet driver but identify it as an updated Vlance driver, so the guest
\noperating system uses that driver. When using the Flexible network
\nadapter, you can have vmxnet performance when sufficiently recent
\nVMware tools are installed. When an older version of VMware Tools is
\ninstalled, the Flexible adapter uses the Vlance adapter (with Vlance
\nperformance) rather than giving no network capability at all when it
\ncan\u2019t find the vmxnet adapter.
\nEnhanced vmxnet<\/strong> \u2014 The enhanced vmxnet adapter is
\nbased on the vmxnet adapter but provides some high-performance features
\ncommonly used on modern networks, such as jumbo frames. This virtual
\nnetwork adapter is the current state-of-the-art device in virtual
\nnetwork adapter performance, but it is available only for some guest
\noperating systems on ESX Server 3.5. This network adapter will become
\navailable for additional guest operating systems in the future.<\/p>\n

Networking Error, IP Address Already Assigned to Another Adapter
\nKB Article 1179
\nUpdated Jan. 07, 2009
\nWhy do I see an error message that \u201cThe IP address XXX.XXX.XXX.XXX\u2026\u201d is already assigned to another adapter?<\/div>\n

Solution
\nUnder certain conditions, you may see the following error message from a Windows guest operating system:
\nThe IP address XXX.XXX.XXX.XXX you have entered for this network
\nadapter is already assigned to another adapter Name of adapter. Name of
\nadapter is hidden from the network and Dial-up Connections folder
\nbecause it is not physically in the computer or is a legacy adapter
\nthat is not working. If the same address is assigned to both adapters
\nand they become active, only one of them will use this address. This
\nmay result in incorrect system configuration. Do you want to enter a
\ndifferent IP address for this adapter in the list of IP addresses in
\nthe advanced dialog box?
\nIn this message, XXX.XXX.XXX.XXX is an IP address that you are
\ntrying to set and Name of adapter is the name of a network adapter that
\nis present in the registry but hidden in Device Manager.
\nThis can occur when you change a network connection\u2019s TCP\/IP configuration from DHCP to a static IP address if:<\/p>\n