ip-pre-up.d
 

I've written a script to set up a firewall before the interfaces come up.

The script is saved as
/etc/network/if-pre-up.d/00-firewall

I've added a line with logger, just to see when it is executed
and now that line is repeated 4 times.

I guess it might be because I've got 4 ip interfaces.

how can I prevent that?

Pretending that you are using a debian system check the man page of interfaces and see if the mapping rule can help you to only run your firewall script ones. Or edit your script in /etc/network/if-pre-up.d and insert a check for the devices and only run the script if the device fits.

man interfaces did help, thanks

sometimes I just don't try all the man pages because I don't believe there would be an entry for stuff.
I tried man network and man if-pre-up without any luck.

I think I'll be able to do something with the variables mentioned in interfaces.

Sometime one does not see the woods for the trees. If you hitting any dead spots or having more question just post and I'll see what I can do.

Thanks for that offer. I might take you up on it.