Configuring eMake and agents for multiple interface communications

You can configure CloudBees Build Acceleration to use two networks for eMake-to-agent communications and select which network to use for a particular build. For example, different eMake client machines can connect to the same cluster using different networks. Before using this procedure, finish setting up your network and host machines.

To configure your system, follow these steps:

Create the runagent.local file (if it does not already exist) on each agent machine with an alternative IP address.

You must create the file in the <install_dir>\<arch>\bin directory.
Add the following line to the runagent.local file:
```
set ::args(-myip1) W.X.Y.Z▼
```
and replace W.X.Y.Z with the alternative IP address of the agent. The primary IP address can still be deduced automatically from the interface that the agent uses to connect to the Cluster Manager, or it can be specified explicitly with “ set ::args(-myip) A.B.C.D ”.
Restart the agents.

Now the agents are configured with an alternate IP address.
Configure the eMake client by adding this command line option (or place it in EMAKEFLAGS ):
```
--emake-ip-set=1▼
```
Alternatively, you can add the following line to the environment:
```
EMAKE_IP_SET=1▼
```

Now the eMake client is configured to use the alternative IP addresses for agents.

If the eMake client machine is connected to the cluster through the alternative network only (as opposed to both networks or the primary network only), you must complete step 4 for builds to proceed.

When an agent provides an alternative IP address, the Cluster Manager web interface displays the alternative IP address in parentheses to the right of the primary IP address.

When primary and alternative IP addresses are used, agent-to-agent file transfers will always use the primary IP addresses of the agents, as will all communications between the Cluster Manager and the agents. The alternative IP addresses of the agents are used for eMake-to-agent communications only, and only when the eMake client requests them.