Go to Main Menu→“View”→“Status Bar” to show/hide the Status Bar.
When you start a BitComet session and are not in “No Listen Port” mode, your client sends a message to a BitComet probe server, requesting that the server send a probe to your IP address and listen port. Your client listens at the port for the probe, in order to determine the port's status. The status light is an indication of, but is not definitive proof of your listen port status.
A gray light means your client did not get a response to the connection attempt, from the probe server. The server may be down and unresponsive. The server may be blocked by your ISP, or may be temporarily unreachable due to network conditions. If this condition persists:
Click here for information and alternative methods to verify that your listen port is open - an open listen port is equivalent to a green status light.)
An yellow light means BitComet successfully requested the probe, but did not detect it at your listen port. This indicates that the port is blocked by one or more firewalls. Your client can therefore reach other clients but other clients can not initiate contact with your client.
If your listen port is blocked you can still transfer files with BitComet, but your transfer speed probably won't be very high.
If the firewall blocking the port is not under your control, then there is probably nothing that you can do about this and your client must operate in “No Listen Port” mode. If you have multiple firewalls, your listen port must be open on all of them. It only takes one to block the port.
A green light means that BitComet requested the probe and received it on your listen port. This indicates that your listen port is open, so other peers can initiate contact with you through your firewall(s). An open port will provide you with the best transfer rates.