View Full Version : IP address using port 68

04-17-2005, 01:31 AM
The following IP address has been trying to get through my firewall constantly on port 68:

When I do a reverse lookup to see who it belongs to it just comes up as belonging to IANA as a reserved IP address.

Am I just clueless here? What's going on?

04-17-2005, 02:01 AM
hmm...weird. I used McAfee visual trace to do the same thing as you did...

What ISP do you use? have you tried emailing a complaint to abuse [at] iana.org?

NetType: IANA Special Use
Comment: This block is reserved for special purposes.
interests me....especially the "Blackhole" bit...:D

I would contact IANA personally and tell them what is going on, if they don't already know. Their servers could, for some reason, be scanning huge IP ranges to try and gain access to people's computers somewhere.

Port 68 bootpd/dhcp

This protocol is used by systems to automaticaly configure systems. In the older days of the Internet, all systems were configured manually. BOOTP was developed to allow agents to be automatically configured. DHCP was a second version of BOOTP that made it easier to configure PCs this way.

You will often see such attempts against firewalls.

is a explanation of port 68's function/purpose.

My firewall blocks multiple port 455 requests from host81-132-115-166.range81-132.btcentralplus.com. I have BT broadband, so I think that it comes from them....However, IANA are not an ISP.

04-17-2005, 02:06 AM
well if you think someone is tring to get into your computer then u should look more into that IP address.

But when i try to look up that IP address, i got no results. If you think is someone like a hacker, spy agent, or whatever then i think you should get PeerGuardian. This program uses almost no memory and it blocks IP addresses like crazy.


Hope you get a solution!

04-17-2005, 03:52 AM
After digging around at IANA I found this


Apparently that IP address is just part of another reserved block of IPs just like the loopback IP or 169.254.x.x. So I guess it is either coming from my ISP or I've inadvertantly turned on some service looking for DHCP on my machine. I am running Linux btw not M$ Windows.

12-23-2008, 01:40 AM
IANA is Internet Assigned Numbers Authority. Port 67 is the port used by a client to connect to a DHCP server in order to send a DHCPDISCOVER message to request a new IP. Port 68 is the port used by a DHCP server to communicate with the client for the same services, because the communication use udp there are a lot of cool things (and horrible things) you can do by manipulating communications on these ports.
By the way, although Microsoft is the company that introduced Dynamic Host Configuration Protocol to the market, it is used by all OS's.
Please let me know if this helps...

12-23-2008, 05:28 PM
3 years later it might...