Moving Router DHCP to server based DHCP

[NateRD1982]

I have been tasked on moving our Router DHCP to a Windows Server based DHCP. We had our change over yesterday and the DHCP server was not issuing IP addresses. Here is my setup, and I think it has to do with subnetting. Client PCs are on VLAN20 with a 255.255.254.0 subnet and my DHCP server is VLAN10 with a 255.255.255.0 subnet. I have my IP range and subnet mask of 255.255.254.0 in my scope and I have just my scope options filled out as we only have 1 scope and in those options I have my Router IP, my 2 DNS servers, and my DNS Domain Name.

What am I missing?

 

[Shad007]

Not sure if you've managed to fix the problem but it looks like your DHCP server can't see your clients as they are masked out. In other words your clients are requesting a dhcp address from your server which they can see but the server cannot reply back to them.

if you are managing acl's through your switch i would suggest to allow vlan 10 to talk to vlan 20 and vice versa (not sure why you have a 255.255.254.0 mask on your client network).

Vlan 10 should be a separate network on a /24 mask
Vlan 20 should be a separate network on a /24 mask
ACL's (access lists) should define whether vlans can talk to one another (not subnet masks)

 

[VinceWhirlwind]

You need to provide the rest of your IP details if you want us to comment.
These should include the server and hosts subnets and default gateway addresses.

Assuming your subnetting makes sense (ie, your /23 subnet doesn't conflict with your server subnet), you may be missing an IP helper on the router.

 

[NateRD1982]

Thank you for your support! In end the we configured the 2nd NIC to be on the same VLAN as our devices that need to access DHCP.

This thread is solved!