Grid Control Agent "Failed to start HTTP listener"

Error:
bash-3.00$ ./emctl start agent
Oracle Enterprise Manager 10g Release 3 Grid Control 10.2.0.3.0.
Copyright (c) 1996, 2007 Oracle Corporation. All rights reserved.
Starting agent ....... failed.
Failed to start HTTP listener.
Consult the log files in: ...../OracleHomes/agent10g/sysman/log

Solution:
To prevent the agent from binding to all IP's in the machine:

- Go to AGENT_HOME/sysman/config/emd.properties
Modify this parameter :

AgentListenOnAllNICs=TRUE

To

AgentListenOnAllNICs=FALSE

- Startup the agents now.

If it doesn't work for you, you should also try to change the port in emd.properties file, EMD_URL parameter.

Also look at the trace file at $AGENT_HOME/sysman/log/emagent.trc , if you have an error like "ERROR http: snmehl_connect: failed to create socket: Too many open files (error = 24)" you should check running agent processes (ps -ef |grep agent), kill them and restart agent... If the agent starts but after a while stops itself again, this may be caused by operating system running out of open file handles limit. Check out the kernel which limits the max open file number for a process for your OS.

Description for these parameters:

AgentListenOnAllNIC: Whether the EMD should listen on all NICs on the current host (the default) or just the NIC associated with the hostname in EMD_URL

EMD_URL: EMD main servlet URL