Netscreen 25 Firewall displays wrong IP addresses
Posted on 2011-04-21
I have a Netscreen 25 firewall.
Today I saw a bunch of outgoing traffic on an IP address that I did not have listed as part of our ip block of computers, although it was a valid IP.
Our static IP range is xxx.xxx.xxx.1 to xxx.xxx.xxx.254 and it was IP .7
So, I blocked all outgoing traffic on .7 using our firewall.
Later I got a compliant from a user they could not access the internet. IP .86 was the IP on their computer.
I am unable to PING .7 or .86. I then unblocked IP .7 and the computer with IP .86 could again access the internet.
So, my question is, how can a computer be configured to use an IP address .86 that I can not PING AND the firewall thinks is a different IP .7. Is this an indication that the firewall is bad?