Default security settings differ for each Linux OS distribution and may require additional configuration to allow connections to the required ports.
NOTE: Starting with Veeam Backup & Replication 10, the traffic port range was reduced from 2500-5000 to 2500-3300. The new port range only applies to newly deployed components after Veeam Backup & Replication 10 is installed. If an environment was upgraded from a version of Veeam Backup & Replication before 10, all existing components that were managed before the upgrade will continue to use 2500-5000.
In most Debian distributions, ports from 2500 to 3300 are opened by default. If connections to the Linux server fail, make sure that Linux OS does not have restrictions for this range of ports.
Use the iptables utility to allow connections for the port range 2500–3300: