my variable '$bgp_ip' still has no value

I just re-downloaded the code from the root node and ran it, the only change I made was to add a print of $bgp_ip, and that variable is definitely not empty. So either the code you have posted here is not the code you are running, or there is some other mistake - for example, perhaps you have a typo in the variable name that is not being caught due to a missing strict. Please either post the actual code you are running or use the tips from the Basic debugging checklist to hunt down the problem in your code.