Reverse DNS (PTR records) is extremely useful. However when your office PC(s) are infected with viruses and basically spamming the entire country it might be quite embarassing.
A well known Irish company ran into this issue earlier this week when a PC or PCs in their office started sending out emails to hundreds of Irish companies (both real and imagined). Unfortunately for the aforementioned company their office IP includes their company name in its reverse DNS entry, so anyone who checks their mail logs could see not only which DSL provider’s network was responsible, but also the actual company responsible.
In the days of broadband you need to take responsibility for traffic coming from your PCs ie. patch them properly and use up to date anti-virus software!!
The Downside To Reverse DNS
Downside? Sounds like an upside to me. If it made businesses serious about security and patching I’d make it mandatory.
Mark
Fair point, but when you’re supposedly a technical company this kind of thing is rather embarassing 🙂