The eG Installation Guide - eG Innovations

Configuring eG Enterprise to Work in NATed Environments
In this case:
Figure 6.2: Agent behind a NAT
When installing the agent, the address of the manager to which the agent must communicate
has to be specified as its public IP - i.e., 209.15.165.127.
On the manager side, the "authentication" setting in the Agents->Settings->Communication
Menu has to be set to "Off". This is because the private IP address 192.168.10.7 is not
accessible to the eG manager (which is actually running on a different Intranet with IP
10.5.20.12). Hence, the manager cannot check the validity of the agent’s IP address directly.
When managing the server via the eG admin interface, the server's IP address must be
specified as 192.168.10.7. To see why this is the case, consider how the agent/manager
communication works. When the agent connects to the manager, it presents its identity - IP
address, nick names, hostname, etc. The manager determines the tests that must be
executed by the agent based on its identity and passes this information back to the agent. In
this case, the NATed public IP of the agent system (209.15.2.3) is NOT known to the agent
(as this is not explicitly configured on the agent system). Hence, servers/applications on the
target system must be managed using the private IP address (i.e., 192.168.10.7).
Although the above scenario has been described in the context of a NATed environment, the same
steps above apply if the agent is communicating to the manager using a proxy server as well.
6.4 Managing Agents in Multiple Private Networks
In some cases (especially in managed service provider - MSP environments), a single manager may be
used to manage multiple private networks. The same private IP address could be used by different
servers in the different networks. For example, server Sa in the first network and server Sb in the
second network could both have the same private IP address 192.168.10.7. Different applications
could be running on these servers. The eG architecture provides an elegant solution to allow these
servers to be managed using a single manager. Both the servers Sa and Sb can be added via the eG
admin interface with the same IP address but different nicknames (e.g., Sa and Sb as in Figure 6.3).
Then, ensure that the Verify if agent is reporting from configured IP parameter in the MANAGER SETTINGS page
(Configure -> Settings menu sequence) in the eG administrative interface is set to No. Since the eG
manager and agents use the nickname as the key to identify an agent/server, servers with the same
IP address can be easily distinguished and managed by an eG manager (see Figure 6.3).
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