I have an issue with two Windows 7 workstations with onboard RealTek Family GBE Controller NICS.
They only ever achieve a maximum linkspeed of only 10MBps. The NICS are Gigabit, but the Cisco Catalyst 2950 switch we have is only rated up to 10/100.
I would expect that (as happens at our other sites) that the NICs would run at 100.
All other workstations (4 of them, XP 32bit) and server (Windows SBS 2003) are connected at 100MBps.
I have disabled Large Send Offload for IPv4 & IPv6 on the NIC (before I did this, the linkspeed was a paltry 1Mbps)
I have had the cables swapped out between NIC and data point (despite old previous workstations working fine with same cabling) Cat 5e cable - issue persists.
If I set the link speed manually to 100MBps on the NIC and on the relevant port on the Cisco Catalyst, the link falls over and will only come back up when I set it back to Auto Negotiate on both the NIC and switchport (it will come back up with only the switchport set to auto). It only reconnects at 10Mbps.
I've updated the NICs to the latest drivers provided by Realtek (http://www.realtek.com/downloads/downloadsView.aspx?Langid=1&PNid=13&PFid=5&Level=5&Conn=4&DownTypeID=3&GetDown=false
Win7 and WinServer 2008 R2 Driver 7.75 and tried it on the previous driver 7.53 to no avail.
Also ran the below (disabling SMB2 to make them perform better with earlier XP and SBS2003 OS)
Large Send Offload v2 (IPv4) - Disable
Large Send Offload v2 (IPv6) - Disable
netsh interface tcp set global rss=disabled
netsh interface tcp set global autotuninglevel=disabled
netsh int ip set global taskoffload=disabled
sc config lanmanworkstation depend= bowser/mrxsmb10/nsi
sc config mrxsmb20 start= disabled
netsh interface tcp show global
We have the same PC's in another site with the same switch, same drivers, same setup and they get 100Mbps without issue.
I've had the PC powered off and unplugged from the mains for 20 minutes to see if it renegotiated at a faster speed upon power up, but it didn't work.
I have been using iperf to track the transfer rates.
Spanning tree is has been enabled and disabled on all ports on the Catalyst switch and the linkspeed on these two machines is still 10 irrespective of whether spanning tree is on or off...
The Windows 7 PCs (brand new) have consistently been 10 times slower than the other PCs on the network.
At the start of the issue, the SBS2003 server and XP machines (all Broadcom Giagbit NICS) were transferring at 10MBps (despite showing 100mbps linkspeed on Catalyst switch), and the Windows 7 machines ran at 1Mbps.
After disabling large send offload on all NICs on all PC's the SBS2003 and XP machines run closer to 100Mbps, but the Windows 7 PCs run at 10Mbps. Link Speed on the Catalyst for XP workstations and server shows 100Mbps, and 10Mbps for the Windows 7 PCs.
Any ideas please? I'm stumped!
Many thanks :-D