Users Guide

Known Issues and Frequently Asked Questions 71
Q. What is the Spanning Tree feature?
A. Most quality routers use the Rapid Spanning Tree Protocol (RSTP) to optimize performance and
remove loops. This can cause delays upto 30 seconds or more whenever a NIC is reset. Resets are known
to happen during BIOS POST, driver initialization, and some network software installation and
configuration. The delay can cause errors when running IPMISH commands. It can also cause a SOL
proxy session to become inactivated. You can configure your router to reduce or eliminate the delay by
enabling the router option edge-port (Dell™ PowerConnect™) or port fast (Cisco). This will allow the
link to remain constant and handle the optimization in real time.
Q: a: I performed a Reboot and Activate Console Redirection command using SOL Proxy, but the
option to press <F2> to enter the BIOS setup never appeared.
b: Why do I see a connection time-out error message when I perform the Power Reset command using
the IPMISH command line tool?
A: When the network switch has spanning-tree enabled, it takes about 30-40 seconds for the
spanning-tree check to make sure there are no loops in the network. During this time, packet forwarding
by the switch is blocked. Therefore, the software cannot communicate with the BMC until the spanning
tree check is complete. When the spanning tree feature is enabled on a edge-port or port fast router, the
network link can be broken for periods of time in excess of 30 seconds while the router analyzes the
network. IPMISH commands can timeout during this process.
a. Disable spanning-tree on the edge-port or port fast router or enable the Spanning Tree Fast option and
try performing a Reboot and Activate Console Redirection command using SOL Proxy again. You
should now be able to enter BIOS setup by pressing <F2>.
b: Disabling spanning-tree will reset the power without an error message.
Q: Why do some key and key combinations, such as <F10> and <Ctrl><Alt><Del>, not work
during console redirection?
A: Console redirection uses ANSI or VT 100/220 terminal emulation, which is limited to basic ASCII
characters. Function keys, arrow keys, and control keys are not available in the ASCII character set, and
most utilities require function keys and control keys for ordinary operations. See "Escape key sequences"
for more information on the same.
Q: Can you use terminal mode simultaneously with BIOS console redirection?
A: Yes. BMC terminal mode can function simultaneously with BIOS console redirection. You can escape
between the BMC’s terminal mode and the BIOS console redirection using the following
Escape sequences:
Press <Esc><q> to switch the system serial port to the BIOS console redirection text stream.
Press <Esc><(> to switch the system serial port to the BMC terminal mode text stream.