Help! Metasploit Unable To Bind

I asked this in the break room already but thought I'd post it here as well. I'm having a ton of trouble with metasploit's handler being unable to bind. I suspect this might have something to do with my network configuration. I am running a Debian Kali Linux Virtual Machine and using Private Internet Access VPN. I know what my WLAN is and I know what my LAN is.... Also....will Metasploit automatically insert your LHOST? While running a module I noticed it was running a LHOST of a certain ip. I can't remember if I set it like that or if Metasploit did. Thanks for your help guys! You have to elaborate more on the problem your having. As far as the LHOST, metasploit will not automatically do if for you (exception for some exploits I beleive). 1\. I guess I have several questions actually. Setting up SET for a web attack, you're asked to input your external ip address. I am running a VPN so I enter the ip assigned to me according to "whatsmyip.com". Then I am asked whether metasploit is on the same ip, and if not, to provide the ip of where it is. 2. If you're successful in setting up the information correctly in SET, when you exploit, you're given an ip address. When you click on it you get a message saying "it worked!". I've been having a hard time trying to figure out which ips go where. For example, when I ifconfig, I am given 3 ip addresses. The first is the ip address eth, the 2nd is the loopback 127.0.0.1 ip, and the third ip is labeled tun0 The 127.0.0.1 is the loopback IP address so I don't think that is the one you will want. The eth address is your private internal IP address. This is probably the one you want. The one that Metasploit is located at. The tunnel IP address is the IP address assigned to you when connected to the VPN. When you use Google or any other site "What is my IP address", the address that is shown here is your external Public IP address. This is how you look to the internet. You will want to learn and study up on NAT (Network Address Translation). NAT translates private IP addresses on your inside network (LAN) to your Public IP address on the internet. Hope that makes sense. :) I think I understand what NAT does....So here's how I was told to understand Router owns a bar. The address to the bar is public and available to everyone. That's the pub ip. Inside the bar is a super secret VIP area that's guarded by Router. It has it's own ip that's private Router has his friend Nat let the cool pple in through doors 80 and 443. Is that correct? I guess my question is, is using NAT absolutely necessary if your target is not on your network. When I was able to successfully run and connect setoolkit that one time, I hadn't touched my router, i.e. changed any settings pertaining to NAT. If NAT is required that wouldn't have happened, right? So if I understand you correctly, other than not doing anything with the loopback ip 127.0.0.1, I also won't do anything with the VPN's tun0 ip, in terms of specifying those ips with metasploit. Yes that is true. There are different types of NAT (static NAT, dynamic NAT, and PAT). NAT can be described as a type of firewall because is keeps internal IPs private and hidden from the internet. NAT is probably enabled on your router. By default, most home routers (Netgear, Linksys) have NAT enabled by default. I believe metasploit won't be on the same IP if you're using the VPN. You will have to sign-off of VPN, and see what your public IP address is (Whats my IP from Google), this will be the IP that metasploit is on. Next, connect to the VPN and use the IP address assigned to you as the external IP. Let me know if this works? actually i was looking for the answer for that questions how to maintain a permanent connection with ur target if its out side ur router once u made it the first time in so far hadnt found anything especially that everytime u came online ur external ip changes and also ur target external ip changes as well