> Source: [sk118713](https://support.checkpoint.com/results/sk/sk118713) # sk118713 - IKEv1 using Diffie-Hellman (DH) group 19/20 fails to encrypt / decrypt packets | Property | Value | |----------|-------| | Solution ID | sk118713 | | Date Created | 2017-07-06 | | Last Modified | 2021-01-19 | | Technical Level | General | ## Symptoms - IKEv1/2 using DH group 19/20 fails to encrypt / decrypt packets. ## Solution This problem was fixed. The fix is included in: * **[Check Point R80.10](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk111841)** * **[Check Point R80.20](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk122485)** Check Point recommends to always [upgrade to the most recent version](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doShowproductpage&productTab=overview&product=446). If you do not wish to upgrade, [contact Check Point Support](http://www.checkpoint.com/services/contact/index.html) to get a Hotfix for this issue. A Support Engineer will make sure the Hotfix is compatible with your environment before providing the Hotfix. For faster resolution and verification please collect [CPinfo](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92739) files from the Security Management and Security Gateways involved in the case. **For SECUREXL SIM package:** **Hotfix installation instructions:** 1. Hotfix has to be installed on ***Security Gateway / each cluster member running on Gaia***. **Note:** In cluster environment, this procedure must be performed on *all* members of the cluster. 2. Procedure: * Using CPUSE - On Security Gateway running Gaia OS R75.40 and above: Make sure to install the [latest build of the CPUSE Agent](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#Latest build of CPUSE and What's New). Refer to [sk92449: CPUSE - Gaia Software Updates (including Gaia Software Updates Agent)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#How to work with CPUSE): * Section "[(4-A-c)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#How to work with CPUSE - How to download and import a CPUSE package - Import instructions for Offline procedure - Gaia Portal)" / "[(4-A-d)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#How to work with CPUSE - How to download and import a CPUSE package - Import instructions for Offline procedure - Gaia Clish)" - refer to import instructions for *Offline procedure* * Section "[(4-B-a)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#How to work with CPUSE - How to install a CPUSE package - Installing a Hotfix package / Minor Version package)" - refer to installation instructions for *Hotfixes* You can also use the [sk111158 - Central Deployment Tool (CDT)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk111158) to install this hotfix on Security Gateways. **Note:** Reboot is required. * Using Legacy CLI - On VSX Gateway running Gaia OS R75.40VS - R77.30; On Security Gateway running SecurePlatform/XOS/IPSO OS: Note: You must be connected either over Console, or LOM card (SSH session could be disconnected). On VSX versions R75.40VS - R77.30, the Gaia CPUSE does not support installation of hotfixes (refer to [sk92449](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#System requirements and limitations) - section "(2)" - "VSX Gateways"). 1. Transfer the hotfix package to the machine (into some directory, e.g., */some_path_to_fix/*). 2. Unpack and install the hotfix package: ***\[Expert@HostName\]# cd /some_path_to_fix/*** ***\[Expert@HostName\]# tar -zxvf sim_\.tgz*** ***\[Expert@HostName\]# ./sim_\*** **Note:** The script will stop all of Check Point services (*cpstop*) - read the output on the screen. 3. Reboot the machine. **For *FW1_WRAPPER* package:** **Hotfix installation instructions:** 1. Hotfix has to be installed on ***Security Gateway / each cluster member /***. **Note:** In cluster environment, this procedure must be performed on *all* members of the cluster. 2. Procedure: * Using CPUSE - On Security Gateway / Management Server running Gaia OS R75.40 and above: Make sure to install the [latest build of the CPUSE Agent](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#Latest build of CPUSE and What's New). Refer to [sk92449: CPUSE - Gaia Software Updates (including Gaia Software Updates Agent)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#How to work with CPUSE): * Section "[(4-A-c)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#How to work with CPUSE - How to download and import a CPUSE package - Import instructions for Offline procedure - Gaia Portal)" / "[(4-A-d)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#How to work with CPUSE - How to download and import a CPUSE package - Import instructions for Offline procedure - Gaia Clish)" - refer to import instructions for *Offline procedure* * Section "[(4-B-a)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#How to work with CPUSE - How to install a CPUSE package - Installing a Hotfix package / Minor Version package)" - refer to installation instructions for *Hotfixes* You can also use the [sk111158 - Central Deployment Tool (CDT)](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk111158) to install this hotfix on Security Gateways. **Note:** Reboot is required. * Using Legacy CLI - On VSX Gateway running Gaia OS R75.40VS - R77.30; On Security Gateway / Management Server running SecurePlatform/Linux/IPSO OS: Note: You must be connected either over Console, or LOM card (SSH session could be disconnected). On VSX versions R75.40VS - R77.30, the Gaia CPUSE does not support installation of hotfixes (refer to [sk92449](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92449#System requirements and limitations) - section "(2)" - "VSX Gateways"). 1. Transfer the hotfix package to the machine (into some directory, e.g., */some_path_to_fix/*). For FW1_WRAPPER package: 2. Unpack and install the hotfix package: ***\[Expert@HostName\]# cd /some_path_to_fix/*** ***\[Expert@HostName\]# tar -zxvf fw1_wrapper_\.tgz*** ***\[Expert@HostName\]# ./fw1_wrapper_\*** **Note:** The script will stop all of Check Point services (*cpstop*) - read the output on the screen. 3. Reboot the machine. **Related Solution:** [sk27054 - Defining Advanced Diffie-Hellman Groups for IKE in Site-to-Site VPN](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk27054). --- # Agent Instructions This content is from the Check Point Support Center (https://support.checkpoint.com), the official knowledge base for Check Point cybersecurity products. ## Navigating This Knowledge Base - **Complete index**: [llms.txt](https://support.checkpoint.com/llms.txt) - **All SK articles**: [SecureKnowledge Sitemap](https://support.checkpoint.com/sitemaps/secureknowledge-sitemap-index.xml) - **SK article URL pattern**: `https://support.checkpoint.com/results/sk/{skId}` - **Markdown responses**: AI bot User-Agents automatically receive `text/markdown` content