The balancing algorithm selects an outgoing link based on source and destination IP address. It does not balance on a per packet basis. The reason is that TCP performance suffers severely when packets are reordered due to different paths in a single TCP connection.
This means that any transmission with the same source and destination IP address will always take the same interface combination. For example, outgoing packets always on WAN 1 to uplink 1 on Sophos UTM, incoming packets always from uplink 2 on Sophos UTM to WAN 1. When a client behind a RED 50 downloads a large file, all incoming packets will be transmitted via one interface only. When a client downloads simultaneous two files from two different servers the incoming packets will be transmitted via either one interface or both interfaces depending on the IP addresses.
Here are the balancing setups:
To configure a RED 50 balancing on Sophos UTM with one uplink, do the following:
Configure the first and the second uplink for balancing.
Note – Do not enter the same IP or name twice.
To configure a RED 50 balancing on Sophos UTM with two uplinks in balancing mode, do the following:
To configure a RED 50 with one uplink on Sophos UTM with two uplinks in balancing mode, do the following:
Note – If uplink balancing is not enabled the dmesg error message 'IPv4: martian source...' will be shown on Sophos UTM.
|© 2019 Sophos Limited
|Sophos UTM 9.600