Computers are getting IP address outside our DHCP range
I have our DHCP address range set to 172.18.1.12 - 150. However, two of the computers have IP address past this range. Why would this happen?
DHCPDNSActive Directory
Last Comment
Perarduaadastra
8/22/2022 - Mon
Krzysztof Pytko
That looks like you have configured them with:
1) Static IP address
2) MAC address reservation is set up
3) The old DHCP server with the old scope is still active
4) IP address is 169.254.x.y/16 (APIPA) that means no connection to DHCP server
That isn't a private IP address space, and so the addresses are routable.
I would suggest changing your internal LAN addressing to 172.16.x.x, which is a private address space. If the problem persists with the new addressing, you know that it is something on your LAN that's causing it.
Member_2_6492660_1
What Ip addresses are they getting?
Are they getting a 169.254.x.x number?
If so they are not finding the DHCP server
If they have vailid ip addresses then they may be manually configured.
When I run Ipconfig /all they both are pointing to a DHCP server that is incorrect. one is getting 172.18.1.50 and the other is .51. Our DHCP server is 172.18.1.8
I can ping 172.18.1.8. Also on the DHCP server 172.18.1.50/51 are in the excluded range.
When I ran the Rogue detection it finds our correct DHCP server as a Rogue server and it finds the 172.18.1.50/51
Krzysztof Pytko
Check if you have no DHCP running on any router device or if there is no DHCP emulation software installed. Just check MAC address of those devices and check the manufacturer
Krzysztof
J.R. Sitman
ASKER
I just typed 172.18.1.50 in IE and found out what it is. It is our Wireless Adhoc device that is supposed to assign IP to wireless devices outside of our DHCP range.
So the question now becomes how do I get the two computers back on the proper DHCP server?
Until I can get the company out here to reconfigure the wireless device, what problems can this create?
I'll post later, off to a meeting. Thanks
DrDave242
If .50 and .51 are giving out different DHCP options (default gateway, DNS servers, etc.) from the ones being given out by the "real" DHCP server, machines receiving DHCP addresses from them could have trouble accessing other resources on the network. If those options are the same, then you may not experience any issues at all unless, for example, you've got firewall rules restricting access based on IP ranges.
Also, a minor point of correction on an earlier respose:
That isn't a private IP address space, and so the addresses are routable.
172.16.0.0/12, which includes everything from 172.16.0.0 to 172.31.255.255, is private, so you're fine in that regard.
1) Static IP address
2) MAC address reservation is set up
3) The old DHCP server with the old scope is still active
4) IP address is 169.254.x.y/16 (APIPA) that means no connection to DHCP server
Can you verify that, please ?
Regards,
Krzysztof