I need help configuring three products: WRVS4400N, WAG325N and WVC200

Question

Hello,
I want your help in three linksys products as mentioned below:
WAG325N ADSL2+ Router
WVC200 PTZ CAMERA
WRVS4400N VPN Router
The computer connections and configuration of above linksys products which I am working with and which are connected with the above three linksys products at present are as follows:
1) I have one server and one laptop.
2) Laptop has two wireless adapters which I use to connect to the routers.
3) The server is connected to the WRVS4400N Router through one of the four ethernet ports mentioned on backside of the WRVS4400N Router. The DHCP of this router is disabled by me and the router's default IP 192.168.1.1 was changed to 192.168.1.12
4) The WRVS4400N router is connected to the Wag325N router for internet access to the server and server is connected to WRVS4400N Router as mentioned in point number 3 above.
5) The WAG325N router is setup as per the instructions mentioned that came with the CD of this router. The only change that I have modified is the router's default IP. I have changed the default IP of WAG325N from 192.168.1.1 to 192.168.1.13 and DHCP is enabled on this router.
The help that I want is step by step as follows:
1) I want to configure the both routers in such a way so that I can access them from anywhere across the world i.e. remotely using internet.
2) I have WVC200 Camera which I setup according to instructions mentioned in the CD and also configured the DDNS service. But when the " RJ45 Cable is connected " to my WAG325N router and Camera, then only the camera works properly. What I want is that after the setup is completed, I want to remove the RJ45 Cable connected from my camera to router and use the camera wirelessly from any location within the range of my above mentioned WAG325N router. I need flexibility to use my camera without cable connections from any location and any rooms of my house. I also configured the port forwarding and DDNS properly. The only problem is that if I remove the Cable after the setup of camera is finished, then the camera access is not working on LAN or internet(through DDNS). Whereas the same works on LAN and internet using the DDNS service, when the cable is physically connected to the WAG325N router. Also I want one more thing additionally other then this. I want to use this camera wirelessly by configuring the port forwarding options on both routers at a same time(i.e. simultaneously at once on WRVS4400N and WAG325N).
3) Now as two DHCP cannot work at a same time and as my routers are connected with each other, So I have disabled the DHCP on WRVS4400N. Here I need help so that DHCP can be enabled on both at a same time. Because if the DHCP is not enabled on WRVS4400N then I have to give IP to the server which is connected with server. If I enable the DHCP then there are two DHCP's at a same time on same network and thus problems occurs in internet access to the server. So, what should I do in such a way so that I do not have to give any IP to my server and set it to automatic.
4) This question is just for my knowledge so that I can use the above mentioned linksys purchases upto full extent possible in future. I want to know what is VPN and how is it usefull? What is the difference between VPN and VPN tunnel? How can VPN be used to access all my network resources connected with my server  in the above situation where my server is connected to WRVS4400N which in turn is connected to WAG325N?
Thanks !
Sincerely
Kalpesh Sharma
[phone]
[phone]
Ahmedabad, India.

Answer 1

for question number 1:
you said that your main router is WAG325N, for you to remotely access the 2nd router is for you to forward the IP addr [192.168.1.12] on your first router and change its management port of your second router that is located on either the security tab or the administration tab on its User Interface
to access your first router open and Internet Explorer and enter
http://[public IP addr]:[management port]
the PUBLIC IP or INTERNET IP is located on the status page of your router
to access your second router just change the management port to
ex.
http://66.77.88.99:8080 first router
http://66.77.88.99:8081 second router
for question number 2:
make sure that you have configured all wireless settings on both your camera and your main router WAG235N, once done save settings and power down your camera and power it back up.
for question number 3:
for you to enable DHCP on both routers your connection can go like so...
from a regular port of your main router going to the INTERNET port of your second router [this way you can enable DHCP on both routers]. INTERNET is no problem, your cesond router will be able to get connection
for question number 4:
VPN - Virtual Private Network
VPN tunnel -is/are connections from router to router [gateway to gateway]
VPN is used to connect a diff network on a diff location for you to have access to the shared filed [it is like a file sharing through the internet]
for you to be able to use VPN tunnel you have to connect to a different VPN router on a diff location. In that way you can get access to the other network