If you are trying to connect to your CA SCM Broker using the machine's Fully Qualified Domain Name (FQDN) and are receiving a -307 comm error, this generally means the client can find the broker machine (FQDN resolves to a valid IP address) and port 5101 is open, but the broker is either down or is known by a different name.
By default the broker name is the same as the hostname of the computer it's installed on. As an example, let's say your CA SCM Broker is installed on a machine with a Fully Qualified Domain Name of "harvesthost.mycompany.com" and a hostname of "harvesthost". Some networks are configured in such a way that you must use the Fully Qualified Domain Name to reference another computer. In this case, if you try to create a broker connection with Workbench using "harvesthost.mycompany.com" you might get this -307 comm error. The reason is that Workbench is finding the broker machine, and getting in through port 5101, but is not finding the broker. Workbench is looking for a broker named "harvesthost.mycompany.com" but the broker is actually known by its shorter hostname of "harvesthost". The solution is to change the name of the broker so that it matches up with the name that Workbench is looking for.
To fix this problem, on your broker machine you should create a system environment variable: Name: RT_FORCE_NODE_NAME Value: harvesthost.mycompany.com
Then restart your broker in this way:
ps -ef | grep bkrd
ps -ef | grep hserver
ps -ef | grep rtserver
Once the broker has been restarted, try to connect from Workbench or the Administrator Tool again using the long broker name "harvesthost.mycompany.com".
The one thing to remember with this fix is that all client machines will have to use the longer Fully Qualified Domain Name to connect to the broker instead of the shorter hostname.