What does a yellow status indicate in an IPsec site-to-site VPN connection?

In the context of an IPsec site-to-site VPN connection, a yellow status typically signifies that not all associations could be established. This status is a crucial indicator for network administrators as it highlights an issue in the configuration or connectivity that is preventing the VPN from functioning as intended.

When a yellow status is presented, it implies that the initial tunnel setup has started, but one or more of the necessary security associations (SAs)—which are vital for successfully encrypting and decrypting traffic—could not be completed. Factors contributing to this might include incorrect pre-shared keys, mismatched encryption or hashing algorithms, or network connectivity issues between the two endpoints.

Monitoring the status is essential, as it helps in the troubleshooting process, prompting administrators to investigate potential misconfigurations or connectivity problems that need to be resolved to ensure a fully operational VPN tunnel. In contrast, a fully established connection would show a green status, while a connection that is temporarily down or still in the process of establishing would indicate different underlying scenarios.