group_replication_ip_allowlist= "203.0.113.0/24,2001:db8:85a3:8d3:1319:8a2e:370:7348, 2001:db8:8b0:40:3d9c:cc43:e006:19e8" As a best practice for Group Replication IP address permissions, Server B (and all other group members) should have the same allowlist as Server A, unless security requirements demand otherwise. If any or all members of a replication group are using an older MySQL Server version that does not support the use of IPv6 addresses for Group Replication, a member cannot participate in the group using an IPv6 address (or a host name that resolves to one) as its Group Replication local address. This applies both in the case where at least one existing member uses an IPv6 address and a new member that does not support this attempts to join, and in the case where a new member attempts to join using an IPv6 address but the group includes at least one member that does not support this. In each situation, the new member cannot join. To make a joining member present an IPv4 address for group communications, you can either change the value of  group_replication_local_address  to an IPv4 address, or configure your DNS to resolve the joining member’s existing host name to an IPv4 address. After you have upgraded every group member to a MySQL Server version that supports IPv6 for Group Replication, you can change the group_replication_local_address  value for each member to an IPv6 address, or configure your DNS to present an IPv6 address. Changing the value of  group_replication_local_address  takes effect only when you stop and restart Group Replication. IPv6 addresses can also be used as distributed recovery endpoints, which can be specified from MySQL 8.0.21 using the  group_replication_advertise_recovery_endpoints  system variable. The same rules apply to addresses used in this list. See Section 18.5.3.1, “Connections for Distributed Recovery” . MySQL Enterprise Backup is a commercially-licensed backup utility for MySQL Server, available with MySQL Enterprise Edition. This section explains how to back up and subsequently restore a Group Replication member using MySQL Enterprise Backup. The same technique can be used to quickly add a new member to a group. Backing up a Group Replication member is similar to backing up a stand-alone MySQL instance. The following instructions assume that you are already familiar with how to use MySQL Enterprise Backup to perform a backup; if that is not the case, please review the MySQL Enterprise Backup 8.0 User’s Guide, especially Backing Up a Database Server. Also note the requirements described in Grant MySQL Privileges to Backup Administrator and Using MySQL Enterprise Backup with Group Replication. Consider the following group with three members,  s1 ,  s2 , and  s3 , running on hosts with the same names: Backing up a Group Replication Member Using MySQL Enterprise Backup mysql>  SELECT member_host, member_port, member_state FROM performance_schema.replication_group_members; +-------------+-------------+--------------+ | member_host | member_port | member_state | +-------------+-------------+--------------+ | s1 | 3306 | ONLINE | | s2 | 3306 | ONLINE | | s3 | 3306 | ONLINE | +-------------+-------------+--------------+ s2>  mysqlbackup --defaults-file=/etc/my.cnf --backup-image=/backups/my.mbi_‘date +%d%m_%H%M‘ \ --backup-dir=/backups/backup_‘date +%d%m_%H%M‘ --user=root -p \ --host=127.0.0.1 backup-to-image Using MySQL Enterprise Backup, create a backup of  s2  by issuing on its host, for example, the following command: 18.5.6 Using MySQL Enterprise Backup with Group Replication 3758