Looks like around June of 2009... http://www.cisco.com/en/US/products/ps5989/prod_r...

Not sure what I was thinking when I said 1 xor 0 = 1 xor 1 = 1... but that is not correct. Just proves that we're all human, right?

BUT, when you're setting up a discontiguous mask for 3 or more IP addresses, you need to forget XOR, and simply use your own logic. Is the bit significant or not... in the case of comparing 1, 0, 1.. the bit is NOT significant, thus it will be set to 1...

Maybe it would be best if I rewrote this article to better explain the logic.

No problem Keith, this was from a Linux server, but it could've just as easily been from a Mac, or a Windows desktop running Cygwin.

My apologies, meeting so many great people that week has led to a bit of name jumble... Thank you so much for having us out, we certainly enjoyed learning more from everyone at NFD2.

Unfortunately I wasn't able to find a way to do that... I ended up having to add some static routes in my network to get to the P2P address on the device I was attempting to fix.

The problem is that when you're dealing with multiple values, you can't treat it as a true XOR.. as a true XOR is between 2 values and the order of operations would affect the output. (101=1 110=0, if that makes sense)

In this case, you're looking at a significant, or don't care bit. Thus, if you have 101, your bit has to bet set to 1, because you don't care about this value. It changes between the 3 IPs you're checking against.

Does that make sense?

Not that I noticed...

You're absolutely correct, not sure how that made it in there, but I've updated the post now.

Exactly why I posted this article.... :)

LOL, and there you go... You ask, and luckily my readers shall help join in!!! Thank you Nathan!