In general, we recommend that only the largest businesses use 10. subnets - in fact, AT&T and other large ISPs use those IPs internally, and, ocasionally, one will arrive at your Astaro because your ISP has made a router configuration error. There's normally no problem if this occurs, but avoiding subnets in 10. just keeps things clearer.
Businesses should use subnets in the 172.16.0.0/12 range. Homes and internet cafes should use subnets in 192.168.0.0/16. This is intended to minimize overlap between subnets when configuring VPNs. I guess that Astaro chose subnets for the VPN Pools in 10.242.0.0/21 for the same reason.
In general, we recommend that only the largest businesses use 10. subnets - in fact, AT&T and other large ISPs use those IPs internally, and, ocasionally, one will arrive at your Astaro because your ISP has made a router configuration error. There's normally no problem if this occurs, but avoiding subnets in 10. just keeps things clearer.
Businesses should use subnets in the 172.16.0.0/12 range. Homes and internet cafes should use subnets in 192.168.0.0/16. This is intended to minimize overlap between subnets when configuring VPNs. I guess that Astaro chose subnets for the VPN Pools in 10.242.0.0/21 for the same reason.