can't use keyboard/mouse on Remote KVM Switch, Spider

Lantronix remote KVM switch, SecureLinx Spider (usb model) is very powerful remote control solution
(even thousands kilo meters away through narrow network, 300kbps).

Process till problem occurred
In the beginning stage, it was easy for end users to connect that kvm to the target machine with my tel assistance.

It seemed better to connect to kvm through HTTPS than HTTP without proxy machine under filtered network.

Test under target Windows XP was perfect without any changes from default configuration.
During target server boot (RHEL4, Dell PE2950, 5 year old), I could see remote screen of POST, OS start, and logon prompt. In ssh terminal, the machine seems recognizing usb (keyboard/mouse) in /var/log/message, but kvm soft/hard keyboard/mouse didn't work.

Rebooting kvm and server didn't fix it.

Solution
Check the box at "Host Interface" -> "Keyboard/Mouse Settings" -> "Force USB Full Speed Mode"
was the quick solution in my case, and everything became fine.

Maybe the target machine doesn't support USB2.0 high speed. "Force USB Full Speed Mode" makes it to USB2.0 Full Speed, the support page says.

Reference
While I was walking down on the Internet, these pages gave me some inspirations. . .

Lantronix SecureLinx Spider Review: Tiny, powerful IP KVM - Other OSes

Under the Spider’s KVM Settings Menu, the default for Keyboard/Mouse settings is Auto, with choices for USB and PS/2. Selecting PS/2 and clicking Apply (Figure 14) fixed the problem without rebooting either the Spider or the server.

Lantronix Spider with Intel DH67BL mobo

That being said, support for USB2.0 at the BIOS level is spotty at best. Some current motherboards work fine with a Spider at the BIOS Setup level, others exhibit strange behavior or just don't work at all.

If you have a PS/2 Spider and are having problems in the BIOS, try going to the Interfaces:Keyboard/Mouse page and changing the Host Interface setting from "Auto" to "PS/2".

If it is a USB Spider, change Host Interface to "USB"

On a USB Spider, also click on the "Force USB Full Speed Mode" check box so that it is checked.
For more information, see "Keyboard/Mouse Settings" starting near the bottom of page 61 in the Spider User Guide.

Japanese faq1 ID#1281

USB virtual drive may possibly block recognizing the usb keyboard.
Then, deactivate usb virtual drive by "Virtual Media Options" -> "Disable USB Mass Storage if no image is loaded"

Japanese faq1 ID#1256

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