Unable to set custom static IP address on CEM3 with older backplane

Symptoms

A custom (static) IP is set on a CEM3 but the new IP does not take effect. The CEM3 may revert to using a link-local address or a DHCP-assigned address rather than the static address that was set. If a static address was already set, it may remain on the old value and not change.

Explanation

Certain very old revisions of Sensor3 backplane may not properly update the static IP address stored in the backplane when it is changed on the CEM3. The backplane will force its internal IP setting back onto the CEM3 when power cycled, overwriting any change that was made on the CEM3. This occurs with CEM3 running version 1.3.0 or later.

Fix

In some cases, the IP can be properly updated with repeated attempts. Disconnect the network from the rack, wait a few minutes, change the IP again, and press the Reset button. If necessary, repeat this up to three times until the CEM3 retains the IP you set after resetting.

If the prompt "Backplane Config Invalid" is displayed after resetting, choose "Use CEM3 Config"; this often indicates that an older backplane is installed in the rack.

If this is unsuccessful, perform a deep clear on the CEM3 to completely clear the config from the CEM3 and backplane, then reconfigure the rack using Quick Setup and set the custom IP.

If a custom IP cannot be set even after a deep clear, contact ETC Technical Services. It may be necessary to have the backplane replaced.