Slow Internet access on Windows 2003 Virtual Server


We have a Hyper-V server on which the Internet response times on a virtual Terminal Server are extremely slow. At another office we have two physical Terminal Servers on dedicated servers and the Internet response is much better (albeit any pages using Flash cause issues and Firefox is much slower than IE).

I have read a number of articles about not using certain offload features of server NICs on a Hyper-V server. The articles imply that these settings are helpful on non-Hyper-V servers, but not when the server runs Hyper-V.

I would appreciate advise on how the NICs on our server should be set.

The Hyper-V server runs Win 2008 R2 Enterprise on a HP ML350 2 x Xeon E5504 @ 2GHz with 30GB RAM, 2 x HP NC326i Dual Port Gigabit server adaptors, 2 x 2-port SAS 146GB drives as a RAID1 array and 4 x 2-port SAS 300GB drives as a RAID1+0 array.

The Hyper-V machine was set up by the installers to run DNS, File and Print Services, Hyper-V and  Symantec Backup Exec runs on this machine.

Virtual machine 1 is Domain Controller/application/file and print server/Symantec Endpoint server, with 8GB RAM, Windows 2003 Enterprise, 1 Virtual processor, 80GB system drive,
100GB Data drive.

Virtual machine 2 is a Terminal Server, with 12GB RAM, Windows 2003 Enterprise, 1 Virtual processor and 80GB system drive.

On both of the Hyper-V machine NICs, the following settings apply:

IPv4 Checksum Offload - Rx & Tx Enabled
Jumbo Packet - Disabled
Large Send Offload Version 1 (IPv4) - Enabled
TCP Checksum Offload (IPv4) - Rx & Tx Enabled
UDP Checksum Offload (IPv4) - Rx & Tx Enabled
and these are reflected on the Virtual machines.

No more than 10 users are on the Terminal Server at any one time, using applications installed on the DC. There are also 7 users who use applications on the DC from PCs connected to the LAN.

The LAN goes through a HP gigabit managed switch, servers run at 1Gbit, Thin Clients/PCs run at 100Mbits.

Connection to the Internet is via a Unix firewall with a 100Mbit LAN connection and an ADSL Annex M broadband connection with 1.4Mbits download/1.2Mbits upload.

Internet response from PCs on the LAN is fast, so the problem clearly points to the virtual server environment.
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Few simple questions:

1. Are the NICs on your VMs synthetic or legacy?
2. Are the network adaptors shared with management OS in the Hyper V networking section? i.e is the box ticked for "allow management operating system to share this network adapter"
3. Is your RAM allocated to your TS, fixed or dynamic?
4. Are the local NICs on the HP server teamed or separate?

jon_kershawAuthor Commented:

Thanks for the response. In answer to your questions:

1. I'm not sure how to check for the NIC type.
2. The first NIC is shared, the second one (Guest VMs) is not.
3. The RAM is fixed.
4. Neither of the NICs are separate, i.e. neither is teamed.


Please check the type of NIC card assigned:
You want it to be a synthetic card.

Is the Hyper-V integration services been installed? Check via Programs & Features?
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jon_kershawAuthor Commented:

Apologies for the delay, but I've been out of the office with no access to the server concerned.

The NIC is synthetic.

Hyper-V integration is installed, but the Best Practices analysis showed it was down-level. I installed the latest version, but no improvement in response times.

It is the slow speed at which the pages are displayed that frustrates the users, much slower than when using RDP to a PC.
In relation to this comment "2. The first NIC is shared, the second one (Guest VMs) is not.", Is the TS routing via the shared or dedicated NIC?
jon_kershawAuthor Commented:
I am not sure how to check this, but only the TS the NIC is shown as 'Microsoft Virtual Machine Bus Network Adaptor' and is shown as having a a connection speed of 10Gbps. The properties show Network Load Balancing present but not in use.

NIC 1 on the Hyper-V machine is called Management Access, NIC 2 is called Child VM.

When I look at the properties for the LAN connection on the Hyper-V machine, it states Connect using Management Access.

When I last checked the properties, The Management Access NIC has a received byte count of 857,975,822,858. The Child VM NIC a count of 31,171,527,776.

Hope this helps
Can you provide some screenshots of your NIC card properties in Hyper-V Networking?
jon_kershawAuthor Commented:
I believe I may have solved the proble. The NIC on the Host machine and the definitions on both of the virtual machines had the IP offload options enabled. I disabled these and the response times immediately improved.

I had read that these options should not be used on virtual machines.

Web browser response times were still not brilliant on remote Thin Clients, especially on sites making extensive use of Flash etc. I have resolved this by using Ericom Blaze RDP instead of the native Windows RDP.

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Seth SimmonsSr. Systems AdministratorCommented:
This question has been classified as abandoned and is closed as part of the Cleanup Program. See the recommendation for more details.
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