I am using a Linksys BEFSR41 switch and I have SPF installed without any advanced rules. Using SPF alone, the traffic log showed a confusing array of Internet 'noise' being rejected and quite a lot of undesirable polls being permitted. However, since installing the switch, I have a very clean traffic log. The only rejections shown in the traffic log are incoming UDP polls from the switch - and I presume these to be pings or other undesirable signals. On the other hand, there are also rejected incoming UDP polls from the DNS server of my ISP. As the Linsys switch is the only device that is supposed to talk to the DNS server, I do not see how those polls are reaching the SPF. Can anyone explain?
Thanks,
Brian