I have an issue regarding my network. One of the machines within the same subnet seems to have its download speed capped at 1 Mbps. Other machines within that subnet hit 11 Mbps or more. The machines are all within one subnet, and that subnet along with one other subnet are both connected to the modem/router which connects out to the internet. Virtustream is the provider.
The problem machine is Windows XP SP3, 32-bit. It has all its drivers updated, the cable has been replaced etc. The issue does not seem to be a physical NIC problem in any way I can deduce.
There is one DNS on each Subnet -> I can ping the machine which hosts the DNS with no problem whatsoever on any machine. Connections between other machines are good - though the problem machine has a lower acceptable packet size (Internet Explorer any packet larger than 30712 bytes does not send at all whatsoever, compared with 40 000 bytes or more on other machines).
(It should be noted that all the machines within this subnet are within one switch. There is a second switch with more machines, but they are not relevant). I am in the process of examining the switch, but unless it is the physical slot which that machine is in - there is no problem cross-machine within the same switch, or across switches (we can see and communicate with the machines across the other switch just fine). There are some issues with the amount of speed communicating across the subnets, but that is a separate issue I believe.
Also, this machine used to run just fine. While I had not been the one to examine it during initial installation, the user reports it ran much faster in the past. This development occurred very recently. I know changes have been made to the DHCP, but the machine, along with all others, show the correct address and the same IPCONFIG information in terms of DHCP, DNS, etc.
When remoting into other machines on the subnet, connection is incredibly slow, and the UI almost non responsive (I can watch it paint the screen in chunks). This is consistent for most machines I remote into. Some run a little better, but none run at acceptable levels.
What haven't I tried? Is it possible the NIC just up and died? What could I check before replacement of hardware begins?