Hello, I want to know if there is an extension for iptables which allows automating setting of mark in the mangle table, using last n bits of source ip, with an optional offset, to do something like : (the network is 192.168.0.0/20, offset 0x100) 192.168.0.0 will have mark 0x100 192.168.0.1 will have mark 0x101 ... 192.168.2.0 will have mark 0x300 ... 192.168.15.255 will have mark 0x10FF This setting of mark should be done on a single rule, since the mark is computed from host bits and offset. It is useful for efficient upload limiting, when SNAT is used, since the source IP is replaced before tc filters see the packet, but I'm sure you knew that. By the way, this kind of auto matching is possible on tc filters, using "hashed filters".