169 address's

[ARMANDO ALVARADO]

Has anyone ever seen this issue where you see 169.x.x.x address from inside going to firewall. We do not have any such routes so this may be hard to find. But if anyone has a idea to try and locate issues like this any help would work. We are using Palo Alto Pan and it is seeing this address's going to firewall interface.

[cadet alain]

Hi,

169.254.x.x/16 addresses are APIPA addresses used by Windows OSes when they can't get an IP address via DHCP.

These are link local addresses, they are not routeable but permit communication with other machines on same link having the same type of addresses.

Regards.

Alain.

[ARMANDO ALVARADO]

I understand so what can we do to keep these from being seen on the network. Can I use a acl to keep this from showing.

[mikedhill]

If your local IP address is returned as 169.254.y.z with a subnet mask of 255.255.0.0, the IP address was assigned by the Automatic Private IP Addressing (APIPA) feature of Windows. This assignment means that TCP/IP is configured for automatic configuration, that no DHCP server was found, and that no alternative configuration is specified. This configuration has no default gateway for the interface and should not pass in a routed environment.

I would begin with the following link.

How to use automatic TCP/IP addressing without a DHCP server: http://support.microsoft.com/kb/220874

[cadet alain]

Hi,

You must determine why these hosts can't contact a dhcp server to get an address.

Regards.

Alain.