sarangi_master
asked on
Strange IP addess being given out !!
I have a windows 2008 server acting as a domain controller / ad and DHCP server, however for some strange reason when i set all computers to automatic IP address they get a IP address of 169.254.51.235
which is nothing like my ip addressing scheme which is more like 192.168.......
I do not have any other DHCP server running on my network yet all machines have strangely got this IP address form somewhere and now cannot connect to the domain?
Please advise further guys !! Thanks
which is nothing like my ip addressing scheme which is more like 192.168.......
I do not have any other DHCP server running on my network yet all machines have strangely got this IP address form somewhere and now cannot connect to the domain?
Please advise further guys !! Thanks
ASKER
The only thing that I can think of that has similar IP address to the one that is given out is my 3COM switches which have Ip addresses similar to 169.254......but how could these give out an ip address to machines on my network ?
169.254 is the MS reserved APIPA address range. It is used if there is no DHCP server available or found. Are you certain you have set up your DHCP server correctly, with an available IP pool?
ASKER
yes everything on my network was recieving the correct ip addresses and then all of a sudden I get this problem every now and again and no one can log in ? At the moment my dhcp server has 3 address leases that are fine....however every other machine is getting the other 169.254 address
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ASKER
dhcp scope is 192.168.0.10 - 192.168.0.240 limited to 3 days ....
routing is set to my router IP address......and not provided by dhcp
I have just deactivated and activated the scope.....still not working...
routing is set to my router IP address......and not provided by dhcp
I have just deactivated and activated the scope.....still not working...
Incase its coming from a rogue DHCP then try Dhcploc.exe. You can also find the DHCP details using ipconfig/all command.
Check your physical connections to the switches, make sure all cables are properly connected, and the switches turned on. Also make sure the Server's NIC actually has a connection to the LAN.
ASKER
where do i get dhcploc.exe from ?
ASKER
all of the below are ok :
Check your physical connections to the switches, make sure all cables are properly connected, and the switches turned on. Also make sure the Server's NIC actually has a connection to the LAN.
Well.. It looks like your DHCP server is not servicing.. Like mentioned above either its run out of IP Address or the DHCP service is not active.
Please check the link below (it contains all the steps that come to my mind but in a systematic manner):
http://technet.microsoft.com/en-us/library/cc779112%28WS.10%29.aspx
Please check the link below (it contains all the steps that come to my mind but in a systematic manner):
http://technet.microsoft.com/en-us/library/cc779112%28WS.10%29.aspx
ASKER
one PC has an IP address of: 169.254.51.235
another has: 169.254.125.213 with subnet masks of 255.255.0.0
another has: 169.254.125.213 with subnet masks of 255.255.0.0
ASKER
where can i find dhcp loc ?
You will need to have the Support Tools installed, which are e.g. located as \support\tools\suptools.ms i file on your Windows XP CD-ROM.
ASKER
I have deleted the scope and added it in again.......and it seems to be working. I have two new address leases within the scope.....however this is a problem that happens every so often and causes disruption as no one can log into the domain...any ideas what the root cause could be? Also the network connections on client pc's sometime also automatically diasble ? This is also strange.....
169.254.x.y/255.255.0.0 is as said the APIPA-range (Automatic Private IP Address) automatically assigned by client on its own when not able to get an address lease from DHCP server.
In DHCP management console, use manage authorized servers to verify it's authorized. As it's a domain member, it's a requirement for domain member to act as DHCP server.
It can be that it's out of addresses and released leases haven't been complete. Use the recouncile scope option when right-clicking server/scope to cleanup DHCP database.
In DHCP management console, use manage authorized servers to verify it's authorized. As it's a domain member, it's a requirement for domain member to act as DHCP server.
It can be that it's out of addresses and released leases haven't been complete. Use the recouncile scope option when right-clicking server/scope to cleanup DHCP database.
basically these are AutoIP addresses, they are defined to be 169.244.x.x/255.255.0.0
If you have a dhcp server running that allows the connection computers (MAC addresses) to be assigned an address and the computer has a dhcp client up and running then they should get for a DHCP request also a DHCP address.
If anything within this communication is not working, or you limited e.g. the distribution of IP addresses to a certain range of MAc addresses, or the DHCP takes too long to answer, the system will fall back to use AutoIP.
If the machine is having such an address, you might try to use
ipconfig /release
ipconfig /renew
If all else fails, you could try to run wireshark on a machine and trace the dhcp request / answer dialogue to get more insight in what is going wrong.
If you have a dhcp server running that allows the connection computers (MAC addresses) to be assigned an address and the computer has a dhcp client up and running then they should get for a DHCP request also a DHCP address.
If anything within this communication is not working, or you limited e.g. the distribution of IP addresses to a certain range of MAc addresses, or the DHCP takes too long to answer, the system will fall back to use AutoIP.
If the machine is having such an address, you might try to use
ipconfig /release
ipconfig /renew
If all else fails, you could try to run wireshark on a machine and trace the dhcp request / answer dialogue to get more insight in what is going wrong.
The latter points to network issues, like cabling or switch/hub failure. Sometimes a network connection interruption is caused by non-standard autonegotiation of (physical) network properties (speed and duplex setting).
Next time a DHCP issue occurs make sure the network connection is working, the DHCP pool has free leases, and then try a ipconfig /release & ipconfig /renew combination in a DOS prompt on the client to try to retrieve a new IP.
Next time a DHCP issue occurs make sure the network connection is working, the DHCP pool has free leases, and then try a ipconfig /release & ipconfig /renew combination in a DOS prompt on the client to try to retrieve a new IP.
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It is likely these problems are caused by wiring and switches. I've solved such problems elsewhere by installing an HP Procurve switch. Not all switches are equal.
Some switches are more equal than others ;-).
Please answer the questions below?
1. What is the IP Address of the DHCP server?
2. Have you configured VLAN in your network?
3. Configure a Static IP in client and check could you able to ping the DHCP Server?
4. Check the Scope is activated in DHCP server?
5. Check is the DHCP server is authorized?
Getting APIPA, it seems to be Client unable to contact the DHCP server.
Cheers,
Prem
1. What is the IP Address of the DHCP server?
2. Have you configured VLAN in your network?
3. Configure a Static IP in client and check could you able to ping the DHCP Server?
4. Check the Scope is activated in DHCP server?
5. Check is the DHCP server is authorized?
Getting APIPA, it seems to be Client unable to contact the DHCP server.
Cheers,
Prem
ASKER
the ip address of the dhcp server is 192.168.0.250
I have not configured vlans on my network, however having said that the switchs that I am using i.e
3com baseline 2916 configure a vlan by default.
DHCP server is fine and I am able to ping it.
However I have realised that the 3com switchs 2916 baseline do cause problems and usually it is these that I have intermittent problems with. Also I have realised that whilst using ghost boot up disks they cannot connect to dhcp server only on the 3com switches, yet work with other switches.
anyone else had problems with 3com 2916 switches ?
I have not configured vlans on my network, however having said that the switchs that I am using i.e
3com baseline 2916 configure a vlan by default.
DHCP server is fine and I am able to ping it.
However I have realised that the 3com switchs 2916 baseline do cause problems and usually it is these that I have intermittent problems with. Also I have realised that whilst using ghost boot up disks they cannot connect to dhcp server only on the 3com switches, yet work with other switches.
anyone else had problems with 3com 2916 switches ?
and have you tried restarting the dhcp service and checking the event logs to see if it is working or not. PIning the server provides no information on the state on DHCP.
also, you mention you can get a DHCP address when connected to some switches and not others. Are the switches on different subnets or behind a router/firewall?
also, you mention you can get a DHCP address when connected to some switches and not others. Are the switches on different subnets or behind a router/firewall?
ASKER
deleting and restarted the dhcp scope seemed to do the trick......thanks
If you have recently changed over to your new DHCP server then you need to look carefully at it's settings as it's not giving out addresses.