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remove old DHCP /24, install new DHCP /23

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kokaina

Technical User
Feb 5, 2004
85
RO
Hello,
I have one DHCP server that give address from 192.168.0.1 /24 , this range is not enough anymore we have more than 254 clients and we need another IP range
I recently purchase a second server and I want to install DHCP on this server with scope 192.168.0.1 /23 ( this give me about 510 address and should be enough ) and I will enable Conflict detection to 1.
Deactivate old DHCP/24 server, activate new DHCP/23 server and wait couple of days until all clients receive IP from new DHCP /23. After that delete old DHCP /24 scope .
Is this plan OK? I should expect to some DHCP-related problems ?

Thank’s
 
Copy the lease file from old to new server so that the new server don't give out ip that other user already are using.
 
Here's the method I ususally use:

1. Build the new scope on the other server, and in that new scope, create a temporary exclusion range that covers the area used by the legacy active scope. When you are ready to start, make it active.

2. Go the the server that's got your legacy scopy and DEACTIVATE the scope. Don't delete it. If you deactivate the scope, when a client tries to renew its address, it will issue a NACK and tell the client to immediately drop its address and find a new one. This will cut your migration time in half.

3. Once there are no more active leases in the old scope, go ahead and remove the exclusion range from the new scope and remove the old scope.

Using this method, there will be no conflicts to worry about.

If a system restarts, it trys to renew its existing lease, and if it doesn't find its original DHCP server, it will continue to keeps its existing address until the original lease time expires. With the NACK being issued like we set up, any restarting client will drop that lease and start from scratch.

ShackDaddy
Shackelford Consulting
 
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