On 03/10/17 09:09, J Doe wrote: > In man I see that the “subnet” option for “mynetworks_style” is > listed as being supported in Postfix < 3.0. Does this mean that > post-Postfix 3.0 this option is deprecated ?
The full line in the docs you're referencing is: (default: Postfix >= 3.0: host, Postfix < 3.0: subnet) That means that the default for this changed in postfix 3.0. It does not refer to support for the subnet setting. > I also note that the “subnet” option is listed as working on Linux > with the following caveat: > > “On Linux, this works correctly only with interfaces specified with > the ifconfig command” > > With ifconfig being deprecated on Linux, does that mean that network > settings specified with newer commands that replace ifconfig will not > work ? I'm not entirely sure, but I would venture to say that it means that ifconfig libraries are used to fetch the IPs and subnets on the system. In linux ifconfig will only return the first address on a given interface. It used to be the case ages ago that if you wanted to assign multiple addresses to an interface you would create aliases for that interface (eg: eth0:0, eth0:1 being aliases for eth0). ifconfig sees those aliases as separate interfaces so it will see the additional IPs just fine, but on newer linux the addresses are assigned via the newer ip command to a single interface and if you query them with ifconfig only the first will show. Also I cannot say for certain how this affects IPv6 addresses, they do seem to be returned correctly with ifconfig, but you'd have to check on your own system(s) to be certain. If you need this then you may very well be better off just dumping the list of IPs to a file and loading them into the mynetworks setting instead. Peter
