IP Addresses Reset ??

[Blaze]

Hi any advice would be appreciated..

I have a domain of over a 100 PC's with the IP address range 192.168.1.1
upwards and the subnet mask 255.255.252.0... all IP addresses are obtained
via DHCP from the DC ....all was working sweet.

Day before yesterday user's were saying they could not log on to some of the
PC's.. and it was saying domain available.

Went and saw that the IP address's were 169.172.70.2 and such with the
Subnetmask 255.255.0.0

These pc's cannot ping the server 192.168.1.1, so I took off the obtain IP
address automatically and put in an static IP from the normal range and set
the mask to 255.255.252, rebooted and it still could not ping the server.

Tried renew and release... that failed because it could not see the DHCP
server

Cleared ARP etc etc.

Took the PC's off of the domain (said that unable to delete account in AD,
changed PC'name) and I am now unable to join the domain even with a static
IP address.. and cannot ping the server

Any Ideas on how to fix this ?

thanks

 

[Miha Pihler]

Hi,

If Windows clients are set to obtain IP from DHCP and DHCP can't be
contacted then the will assign themselves IP 169. ... etc (it is called
APIPA). Now the real question is, why they can't contact DHCP? Can you check
to see if DHCP is up and running, has enough IPs to give out etc. Also make
sure your other network equipment is working (e.g. switches, hubs, routers,
.... etc..)

Mike

 

[SB]

Clients can't contact the DC/DHCP machine. Cable, card, etc.


Shay

 

[Dave]

the 169.172 ip's are indications that the pc's can't see the dhcp server.
if there are several of them i would suspect either the dhcp server or a
hub/switch/router problem. try manually assigning them an ip in the proper
range and see if they can ping their gateway router and dhcp server.
removing them from the domain was a waste and will just cause more work to
put them back on later since it is a lower level problem than that.

 

[PietervS]

I have a domain of over a 100 PC's with the IP address range 192.168.1.1
upwards and the subnet mask 255.255.252.0... all IP addresses are obtained
via DHCP from the DC ....all was working sweet.

Why on earth would you want so many addresses in your network if you only
have 100 PC's? Why not use a 255.255.255.0 subnet?

But to address your problem: Are there any available adress leases left on
the server? Have you tried restarting the DHCP services?
Are all PC's experiencing this problem, or just a few? In the first case: if
restarting the DHCP services doesn't help, restart the server because the
server nic might be having a problem. If needs be, replace that card. In the
second case: are all PC's on one segment, switch or hub? If so, there might
be a nic causing jabber on the segment or the switch or hub might be faulty.

Hope this helps,

best regards,

Pieter

 

[Blaze]

Thanks Guys..... silly me LOL

Why on earth would you want so many addresses in your network if you only
have 100 PC's? Why not use a 255.255.255.0 subnet?

But to address your problem: Are there any available adress leases left on
the server? Have you tried restarting the DHCP services?
Are all PC's experiencing this problem, or just a few? In the first case:
if restarting the DHCP services doesn't help, restart the server because
the server nic might be having a problem. If needs be, replace that card.
In the second case: are all PC's on one segment, switch or hub? If so,
there might be a nic causing jabber on the segment or the switch or hub
might be faulty.

Hope this helps,

best regards,

Pieter

 

[3millers]

The 169 ip means that the operating system isn't even talking to the
ethernet card. You'll find that you can't release/renew this IP because of
that.

As a last resort, if none of the suggestions here work, power down the
computer, remove the ethernet device, start it back up to a full boot, shut
it down, and reinstall the device. OR install a new ethernet device.
Particularly with Win XP, this method works when all else fails.

 

[jjw]

let me correct some information.....a 169.254.x.x does NOT mean that the
operating system is not talking to the network card, in fact, if u get a
169.254.x.x address, you know that the operating system IS talking to the
network card, because it is the operating system (windows only) that assigns
the 169.254.x.x ip address. Windows will assign an ip address in the
network of 169.254.0.0 when both of these conditions are met: the card does
not have a static ip address, AND it cannot find a dhcp server to get an ip
address from.

The reason that u can't release/renew is this: those commands are for dhcp
assigned ip addresses only, so if u have a 19.254.x.x address, it won't
release it because it wasn't assigned by a dhcp server. The reason that it
won't renew is the same reason that it got a 169.254.x.x address in the
first place: it can't find a dhcp server.

a 169.172.x.x address is a valid ip address...only 169.254.x.x addresses are
addresses that are assigned by Windows. So if u are getting a 169.172.x.x
address, and it's not statically assigned, then you have a misconfigured
dhcp server, or you have multiple dhcp servers on the network. However, if
u manually enter in all the ip address information correctly, and you still
cannot connect to the domain, then the problem is not the dhcp server. I do
not think u correctly entered the ip address info correctly, because u said
u set the subnet mask to 255.255.252....you might wanna check that.

jjw