Sep 29, 2016 · DH Group-2 SHOULD NOT be used. Use DH Group-14. Use RSA-3096 certificates. Use AES128 encryption. SHA1 (Main-Mode) can be used. SHA256 is a better alternative. Use HMAC-SHA1. It is not the same thing as SHA1; Theses tips serve as baseline security -a starting point. Registry Solution: Create a registry key that enforces modern cipher and

Both sides first have to agree on a "group" (in the mathematical sense), usually a multiplicative group modulo a prime. By default, Check Point Security Gateway supports Diffie-Hellman groups 1, 2, 5 and 14 (since NG with AI R55 HFA_10) and groups 19, 20 (since R71). RFC 3526 defines new DH groups, numbered from 15 to 18. DH Group: The Diffie-Hellman (DH) group are the group of numbers used to create the key pair. Each subsequent group uses larger numbers to start with. You can choose Group 1, Group 2, or Group 5. The VPN Uses this during IKE negotiation to create the key pair. Encryption: This is the method for encrypting data through the VPN Tunnel. The For example, the IKEv2 main mode policies for Azure VPN gateways utilize only Diffie-Hellman Group 2 (1024 bits), whereas you may need to specify stronger groups to be used in IKE, such as Group 14 (2048-bit), Group 24 (2048-bit MODP Group), or ECP (elliptic curve groups) 256 or 384 bit (Group 19 and Group 20, respectively). Dec 12, 2019 · Non-Meraki / Client VPN negotiation: msg: invalid DH group 19. Dec 12 15:03:46 : Non-Meraki / Client VPN negotiation: msg: invalid DH group 20. Dec 12 15:03:46 : Non-Meraki / Client VPN negotiation: msg: received broken Microsoft ID: MS NT5 ISAKMPOAKLEY: Dec 12 15:02:59 : Non-Meraki / Client VPN negotiation: msg: invalid DH group 19. Dec 12 15

DH Group specifies the Diffie-Hellmen Group used in Main Mode or Phase 1. PFS Group specifies the Diffie-Hellmen Group used in Quick Mode or Phase 2. IKEv2 Main Mode SA lifetime is fixed at 28,800 seconds on the Azure Stack Hub VPN gateways. The following table lists the corresponding Diffie-Hellman Groups supported by the custom policy:

Group 1, Group 2 (default), Group 5, or Group 14 – Select Group 2 from the DH Group drop-down menu. NOTE: The Windows XP L2TP client only works with DH Group 2. Select DES , 3DES (default), AES-128 , AES-192 , or AES-256 from the Encryption drop-down menu. "DH Group 2 is still supported but it has the lowest priority when finding a proposal match. Both L2TP over IPSec and Cisco IPsec now support DH Groups 14, 5, 2, in that order of preference. For aggressive mode, the VPN client will try first with DH Group 14; if it fails, it will try again with DH Group 2." The table shows no Group 2. Under IKE Proposal, enter Proposal Name whatever you like, select Authentication, Encryption and DH Group, we use MD5, 3DES, DH2 in this example. Step 2 : Click on Add . Step 3 : Click on IKE Policy , enter Policy Name whatever you like, select Exchange Mode, in this example we use Main , select IP Address as ID Type.

When PFS is enabled the phase 2 DH group is hardcoded to the same group that is selected in DH Group. Dynamic Routing: Enable or disable the use of a virtual tunnel interface (VTI). This will specify that the VPN configuration is either policy based (off) or route based (on).

Similar to my test with Diffie-Hellman group 14 shown here I tested a VPN connection with elliptic curve Diffie-Hellman groups 19 and 20. The considerations why to use these DH groups are listed in the just mentioned post – mainly because of the higher security level they offer. set vpn ipsec ike-group FOO0 proposal 1 dh-group 14 set vpn ipsec ike-group FOO0 proposal 1 encryption aes128 set vpn ipsec ike-group FOO0 proposal 1 hash sha1. 4. Create the ESP / Phase 2 (P2) SAs and enable Perfect Forward Secrecy (PFS). set vpn ipsec esp-group FOO0 lifetime 3600 set vpn ipsec esp-group FOO0 pfs enable set vpn ipsec esp-group