The keyboard, video, mouse (KVM) console on the Cisco Unified Computing
System Manager (UCS Manager) allows access to video output for a particular
blade or service profile. This document provides the troubleshooting
methodology to examine failed KVM sessions on Cisco Unified Computing System
(UCS) B-Series servers.
The scenarios, symptoms, and steps listed in this document are written
for troubleshooting issues after the initial setup is already completed. For
initial configuration refer to this document:
Computing System KVM Console Access to Blade Server Configuration
The information in this document is based on the Cisco UCS Manager and
Cisco UCS B-Series Blade Servers.
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Technical Tips Conventions for more information on document
Although there are many sources for KVM failure, mis-configurations and
Java issues are among the most common failure points. While this document
assumes the configuration was functional at one time, it focuses on
troubleshooting the components involved in a successful KVM launch. Failure
Network connectivity for the entire path of the blade Cisco
Integrated Management Controller (CIMC) to client browser.
Java complications on the client in an attempt to access the
UCS Manager failures and defects, which impact
Prior to troubleshooting these failure points, it is best to first
examine the scope of the problem:
Has a single KVM failed, or are all KVMs in the system affected?
Can the KVM be accessed from another machine in the network, or do
all work stations exhibit the same behavior?
If you are unable to ping the KVM IP address, which was assigned
from the management (MGMT) IP pool, you must verify that the IP pool addresses
are within the same subnet as the management IP address assigned to the fabric
interconnect. If the pool does not match, all KVMs that receive IP addresses
from this pool are impacted.
Verify TCP port 2068 is not blocked by the access control list (ACL)
or firewall between client and blade CIMC. With this port closed, it results in
failure to connect to any UCS KVM.
Verify browser configuration to ensure HTTP proxy does not break
If you are unable to ping the KVM IP address, check which fabric
interconnect manages the instance for the blade and verify if it responds. If a
fabric interconnect suffers from a failed/down mgmt0 interface, all blades that
are managed by it experience KVM accessibility issues.
To verify the management instance of the blade, choose the blade from
Equipment > General >
If you are able to ping the KVM IP address, but still not able to
connect to the KVM, you may have a duplicate IP address in the network. One way
to verify this is to statically assign a new IP address that you know is not in
use to the blade. If the host can be taken down, decommission the blade in
question and then try to ping the KVM IP address again. If it is still
successful, that IP is duplicated in the network. Remove the IP from the other
device, or adjust the UCS MGMT IP Pool to not include that
Verify that the proper Java version is installed. The UCS Manager web
page lists the requirements and links for tested java
Monitor and collect Java logs from the Java Control Panel when you
launch KVM. Click Start > Enter Run >
Enter javaws -viewer.
Clear Java cache — In the Java Control Panel > Click
General > Temporary Internet Files >
Click View. It launches a Java Cache Viewer. Delete all the
Does the standalone KVM launcher work? You can bypass the KVM
launcher and UCS Manager with the kvm.zip.
First, you must create an Intelligent Platform Management Interface
(IPMI) policy/user and add this to the affected blades service profile (this is
Go to http://<ucs manager ip address>/kvm.zip to download the
Unzip and run the launchkvm.bat file. It then prompts you for an IP
address of the server (KVM address found in UCS Manager), and the IPMI user
name and password you
There are very few defects related to KVM connectivity on the UCS
Manager, however, to investigate anomalies on the UCS, use these commands and
Verify Fabric Interconnect IP Tables:
UCS-A# connect local-mgmt
UCS-A(local-mgmt)# show mgmt-ip-debug ip-tables
Monitor blade CIMC messages file:
connect cimc [x/y] (where x is the chassis and y is the server)
UCS-A# connect cimc 2/1
Escape character is '^]'.
CIMC Debug Firmware Utility Shell [ support ]
[ help ]# messages
Use the tail command to review the Port to Application Mapping (PAM)
proxy file from UCS Manager. This can be done live or from technical support
UCS-A# connect local-mgmt
UCS-A(local-mgmt)# tail-mgmt-log svc_sam_pamProxy