The Network Layer

The Network layer handles connectivity of the host system to the network, and includes packet traffic transmitted to and from the server. An eG agent tracks the status of the network layer to determine whether the network link to the target host is available or not, the bandwidth available on the network link, and to the rate of packet transmissions to and from the host. For monitoring, an eG agent uses two tests (see Figure 1):

  • Network test that monitors the connectivity to and from a host. An external agent executes this test.
  • NetworkTraffic test, which is executed by an internal agent. This test tracks the rate of packets received and transmitted by each of the network interfaces of a host. A separate set of results is reported for each network interface of the host. For example, Figure 1 depicts the test results for a host with a single network interface that is named en0.

Figure 1 : The tests that map to the Network layer of a Linux server