Hi Usman Khan1 

Please verify the authentication mechanism in PPTP VPN adapter, it should be the same as configured for PPTP VPN configuration in the firewall.Enable CHAP authentication

To set authentication type as CHAP go to the command line of the XG Firewall and do the following.

1. 1. Choose Option 4. Sophos Console from the menu.
   2. Type the following command to enable CHAP authentication:
      set vpn pptp authentication CHAP

CHAP authentication is now enabled.

1. 1. To set MS-CHAPv2 use the following command:

set vpn pptp authentication MS-CHAPv2 encryption STRONG

Please make sure that lease IP range should be different than other VPN configuration and other configured network, for more details please verify the below given link.

https://community.sophos.com/kb/en-us/125662

https://community.sophos.com/kb/en-us/125372

Thank you !

My question regarding your answer is that will it solve my problem? We have set Static IP for PPTP users,but Still Getting IP Lease Failed Message.

Hi Usman Khan1 

Bind a PPTP User to Specific IP

To bind a PPTP User to IP Address:

1. Navigate to Configure > Authentication > Users.
2. Go to the User > PPTP*.
3. Select Enable.
4. Enter the IP Address.
   
   
5. 
   
   
   Note: Ensure that the IP Address is part of the Lease Range mentioned in PPTP General Settings.
   
   
   

But Sophos Support Team Asked to ensure that IP Address Should not be part of Lease Range!

Hi Usman Khan1 

If you are working with a technical support engineer, can you please share the existing service request number?

Service request number is 8932805 regarding "IP lease Failed Issue"  but I have try both methods ,still not working.

Hi Usman Khan1 

Thank you for providing the service request number, I have checked the service request and found that the engineer able to login successfully, you have provided a certain IP address to verify in your last communication email in the service request, I will discuss it further with the engineer and support team will get back to you with their findings. Thank you for your patience.

Thank you for Support. Waiting for Solution