Web based VPN issue wheras anyconnect and VPN client working fine

Question

Experts,
We have Cisco ASA 5540 and im running into issues with accessing the webbased VPN(https://X.X.x.x).there are about 8 VPN profiles configured and im unable to login using any of the profiles whereas VPN client and Cisco Any connect are working fine. on accessing web based VPN after providing  the login credentials and hit enter the page is getting refreshed and it throws me back to the same login page again. This is the Production ASA and i cannot run debug.
Kindly, provide me your valuable inputs.
Thank you!

Answer 1

Your problem is the NAT-config. First, the following line is not needed as RDP doesn't work ober UDP:
ip nat inside source static udp 192.168.10.136 3389 interface Dialer0 3389
Then, the following command causes the problems:
ip nat inside source static tcp 192.168.10.136 3389 interface Dialer0 3389
With that the router assumes that the server 192.168.10.136 should always be reached through the IP of dialer0 and does a translation.
There are a couple of ways to resolve the problem, but they all have some drawbacks ...
1) Only access the server through VPN. For that you just delete the NAT-statement above (the one with tcp) and you should be able to reach the server through the VPN.
2) Restrict the NAT to don't do a translation if a VPN-peer is accessing the server.
For that you need to attach a route-map to the NAT-statement. But that won't work with the "interface"-keyword in the NAT-Statement. But you can use this if you get a fixed IP from your provider.
3) Assign a second IP to the RDP-server. The original IP which is used in the NAT-statement is used for accessing the server without the VPN, the second IP is used for accessing the server through VPN.
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