2/5/17 - Locally hosted Minecraft Server running 1.2.5 server jar, allowed external connection through appropriate port forwarding.
2/10/17 - No changes to Minecraft Server files/properties, updated to new launcher, resulted in "Failed to Login: Bad Login" statement for myself and friend trying to connect externally.
Important Note - I can connect to Minecraft Server in the latest release 1.11.2 when changing the client and server jars accordingly, The issue seems to be with Minecraft version 1.2.5.
Attempts to resolve issue:
Complete re-install of Minecraft Client - issue prevailed
Complete re-install of Minecraft Server - issue prevailed
Other Notes - Nothing else was updated other than the launcher between the instance on 2/5/17 and 2/10/17.