The Idrac card is occasionally unavailable for processing

In the R620 server, there are often problems with Idrac being unable to connect, or the number of users exceeding the limit, there are several ways to try it:
1, upgrade the firmware of the Idrac card
Download and upgrade the latest 1.57.57 version of FIRMWARE:HTTP://WWW.DELL.COM/SUPPORT/HOME/US/EN/04/DRIVERS/DRIVERSDETAILS?DRIVERID=XH6FX
This version of the bug fix mentions a little:
–fix for issues so cause iDRAC7 sluggish responsiveness after a prolonged period of time (approx. 45-100 days, Dependin G on the usage). In some cases, if the Idrac are not reset, the Idrac could become unresponsive and requires a server AC Power on reset. This issue is introduced in firmware release 1.50.50 and fixed in 1.56.55.

This release resolves an issue that could be unresponsive after 45-100 days of Idrac startup.

2. Kill Timeout Connection session
There are 2 ways of doing this:
A. Restart the BMC card
Execute command: ipmitool mc Reset Cold , once the BMC card is restarted, all sessions will be reset and released.

B. Kill the timeout session
If the BMC card is allowed to connect remotely over the network
Ipmitool LAN set 1 access on

or turn it on in the next place.
IDRAC settings = = Service + VNC Server = timeout

Or, under the Idrac card, this place is set:
IDRAC settings = Network = IPMI settings = enable IPMI on LAN

It is also recommended that the timeout values for Web server and SSH services be properly lowered:
IDRAC settings = = Service + Web Server = timeout
IDRAC settings = = Service + SSH = Timeout
IDRAC settings = = Service + Telnet = Timeout
IDRAC settings = = Service + VNC Server = timeout

Use the Racadm tool (the installation of the Racadm tool) to close the timeout session, you can first view the current session connection situation, for example:
[15:41:[email  protected]:~] #racadm-R 10.59.xx.xx-uroot-p "xx" Getssninfo
Security alert:certificate is Invalid–self signed certificate
continuing execution. Use-s option for Racadm to stop execution on certificate-related errors.
Ssnid Type User IP Address Login date/time
—————————————————————————
SSH root 10.5.xx.xx 11/18/2014 15:38:43
GUI root 10.5.xx.xx 11/18/2014 15:40:27
Racadm Root 10.59.xx.xx 11/18/2014 15:41:17
SSH root 10.59.xx.xx 11/18/2014 15:41:18

Then execute the following command to close the timeout session connection
[15:40:[email protected]:~] #racadm-R 10.59.xx.xx-uroot-p "XX" Closessn-i 25
Security Alert:certificate is invalid–self signed Certificate
Continuing execution. Use-s option for Racadm to stop execution on certificate-related errors.
Session closed successfully.

The Idrac card is occasionally unavailable for processing