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> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/365601) in GitLab 15.1 [with a flag](../../administration/feature_flags.md) named `group_level_git_protocol_control`. Disabled by default.
FLAG:
On self-managed GitLab, by default this feature is not available. To make it available, ask an administrator to
[enable the feature flag](../../administration/feature_flags.md) named `group_level_git_protocol_control`. On GitLab.com,
this feature is available.
You can set the permitted protocols used to access a group's repositories to either SSH, HTTPS, or both. This setting
is disabled when the [instance setting](../admin_area/settings/visibility_and_access_controls.md#configure-enabled-git-access-protocols) is
configured by an administrator.
To change the permitted Git access protocols for a group:
1. On the top bar, select **Main menu > Groups** and find your group.
1. On the left sidebar, select **Settings > General**.
1. Expand the **Permissions and group features** section.
1. Choose the permitted protocols from **Enabled Git access protocols**.
> - Support for specifying multiple email domains [added](https://gitlab.com/gitlab-org/gitlab/-/issues/33143) in GitLab 13.1.
> - Support for restricting access to projects in the group [added](https://gitlab.com/gitlab-org/gitlab/-/issues/14004) in GitLab 14.1.2.
> - Support for restricting group memberships to groups with a subset of the allowed email domains [added](https://gitlab.com/gitlab-org/gitlab/-/issues/354791) in GitLab 15.1.1
You can prevent users with email addresses in specific domains from being added to a group and its projects.
When you share a group, both the source and target namespaces must allow the domains of the members' email addresses.
NOTE:
Removing a domain from the **Restrict membership by email** list does not remove the users with this email domain from the groups and projects under this group.
Also, if you share a group or project with another group, the target group can add more email domains to its list that are not in the list of the source group.
Hence, this feature does not ensure that the current members always conform to the **Restrict membership by email** list.
## Prevent group sharing outside the group hierarchy
You can configure a top-level group so its subgroups and projects
cannot invite other groups outside of the top-level group's hierarchy.
This option is only available for top-level groups.
For example, in the following group and project hierarchy:
- **Animals > Dogs > Dog Project**
- **Animals > Cats**
- **Plants > Trees**
If you prevent group sharing outside the hierarchy for the **Animals** group:
- **Dogs** can invite the group **Cats**.
- **Dogs** cannot invite the group **Trees**.
- **Dog Project** can invite the group **Cats**.
- **Dog Project** cannot invite the group **Trees**.
To prevent sharing outside of the group's hierarchy:
## Manage group memberships via LDAP **(PREMIUM SELF)**
Group syncing allows LDAP groups to be mapped to GitLab groups. This provides more control over per-group user management. To configure group syncing, edit the `group_base`**DN** (`'OU=Global Groups,OU=GitLab INT,DC=GitLab,DC=org'`). This **OU** contains all groups that are associated with GitLab groups.
Group links can be created by using either a CN or a filter. To create these group links, go to the group's **Settings > LDAP Synchronization** page. After configuring the link, it may take more than an hour for the users to sync with the GitLab group.
For more information on the administration of LDAP and group sync, refer to the [main LDAP documentation](../../administration/auth/ldap/ldap_synchronization.md#group-sync).
NOTE:
When you add LDAP synchronization, if an LDAP user is a group member and they are not part of the LDAP group, they are removed from the group.
### Create group links via CN **(PREMIUM SELF)**
To create group links via CN:
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1. Select the **LDAP Server** for the link.
1. As the **Sync method**, select `LDAP Group cn`.
1. In the **LDAP Group cn** field, begin typing the CN of the group. There is a dropdown list with matching CNs in the configured `group_base`. Select your CN from this list.
1. In the **LDAP Access** section, select the [permission level](../permissions.md) for users synced in this group.
1. Select **Add Synchronization**.
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### Create group links via filter **(PREMIUM SELF)**
To create group links via filter:
1. Select the **LDAP Server** for the link.
1. As the **Sync method**, select `LDAP user filter`.
1. Input your filter in the **LDAP User filter** box. Follow the [documentation on user filters](../../administration/auth/ldap/index.md#set-up-ldap-user-filter).
1. In the **LDAP Access** section, select the [permission level](../permissions.md) for users synced in this group.
1. Select **Add Synchronization**.
### Override user permissions **(PREMIUM SELF)**
LDAP user permissions can be manually overridden by an administrator. To override a user's permissions:
If a user sees a 404 when they would usually expect access, and the problem is limited to a specific group, search the `auth.log` rails log for one or more of the following: