I would like to block any inbound connection on a certain port when coming from users connected trhouth a certain domain (provider). For example :
block inbound connections on port 25 from users with domain xxx.dsl.telesp.com.br
this means for example 200-204-120-100.dsl.telesp.com.br would be blockedwhen attempting to access port 25, as well as would 201-117-100-100.dsl.telesp.com.br … etc.
Is this possible using the domain field in rules ??
If yes can you tell me how to build such a rule ??