I have a 2820vn and I'm using the WAN2 port to connect to BT Infinity.

We have a fixed IP address given by BT xx.xx.xx.38. Behind that we have a five public IP pool of xx.xx.xx.33 - 37.

In PPOE WAN setup tab I have the log-in set and Fixed IP ticked. Its set to xx.xx.xx.38.

I have IP Alias (Multi-NAT) set and Index 1 is xx.xx.xx.38. That is followed by my IP Public pool on indexes 2 to 6.

I notice I have each index set to "Join NAT IP Pool".

Here is the problem. Internet access is fine but on 1And1 webmail we get an error stating that the IP address of teh client has changed so the user cannot log-on.

When we did a "Show My IP" it was xx.xx.xx.33 and NOT xx.xx.xx.38, which is the fixed IP address of our router. Do I get this problem because I should have ONLY let the first IP Alias Index 1, "Join the NAT IP Pool" and left all the others unticked.

Do I guess that the Vigor has chosen a non-fixed Public IP from the pool when I should have just stuck to one NAT IP?

Thanks

I solved it. The clue was in my question. The "Help" says that if you select more than one IP for the NAt pool then you will get a random public IP address from the pool. It also warns that some banking and secure systems will not like it.