1 Reply Latest reply on Aug 10, 2012 10:54 AM by cribeiro

    Firewall alias address with '255'


      We have a customer who have used a 'class-b' '/16' subnet mask on one of their Firewall interfaces.  One of the interface addresses that they have then used is 172.x.x.255.  Is this in any way a legal address? In theory it isn't the broadcast address, which would have 255 in the last two octets, but I'm not convinced that you can use 255 at all? And they are getting some strange traffic that's showing up on the standby firewall of their HA Pair, so I was just wondering if this might be the reason?





        • 1. Re: Firewall alias address with '255'



          The 255 in the last octet doesn't mean that it is the Broadcast address. If you have Broadcast address is But you Can use the IP has a host. It depends on the Net Mask. This example:
          Hosts: to 30

          I hope this helps you