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DHCP Gets wrong Subnet mask

I have a problem were when systems power up they will get a network address ( for example and a subnet mask of

I have an application that is sensitve to this and will not let users run. If we do a release and renew for that same workstation then they will get the address and proper subnet mask of

any ideas?


Re: DHCP Gets wrong Subnet mask

What component of your network is doing the DHCP service?

Is it possible that there are two DHCP services running on two different systems (one with the proper mask, one with natural mask) ?

Have you checked your DHCP scopes for conflicts?

Gotta know...


Community Member

Re: DHCP Gets wrong Subnet mask

Hi Scott Thank's for your reply. There is only one DHCP Server on the network that we are aware of. We have tried to find another DHCP server but came up with none at this point. I have not looked at the Scopes myself yet but I have been told that everything looks ok from that perspective. But you could be right it may very well turn out to be a scopeing issue and I will have to look at that further.



Community Member

Re: DHCP Gets wrong Subnet mask

We have the same thing. Internally we run a Class C Subnet. All PC's using DHCP from an NT Server. The scopes are fine. It is using the correct subnet mask. When a client PC's lease expires it gate a Class A subnet Mask ( ) instead of a class C ( ) If I do a release and renew it gets the correct Mask. To stop the this from repeating itself I am setting DHCP renewal at never expire.

I would love to know the cause. Something to do with our VPN over ADSL or our router I bet.

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