Using 1 DHCP server for multiple VLANs

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Hi, I am hoping you can provide some advice please?

I have a setup which consists of a 7450 and a number of 7150 switches. I am using D-PSK to drop clients onto their own VLANs (there are around 150 of them).

The VLANs are set up on the switches but I am trying to work out how to handle the DHCP. Should I run a DHCP server for each VLAN or can I run one DHCP server that covers all VLANs with 1 very large IP range and then subnet this up and set the VLAN IP addresses and DHCP helper on each VLAN to allow users to end up in their own VLAN and only able to communicate with other devices within their VLAN (so only devices which use the same D-PSK) or am I missing something here?

Sorry if I have the terminology wrong - I'm one of those Sales types rather than a techie ;)
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Darren Gauntlett

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Posted 2 weeks ago

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Darren Gauntlett

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Sorry I forgot to add, currently the DHCP server is not running on the 7450
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Scott Farrand

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This can quickly head down a rabbit hole.

In a nutshell

Windows servers can easily be configured to lease addresses for multiple network segments. (Google is your friend, there's a bunch of how to's for this type of configuration out there)

For the ICX series switches, in the "Interface ve x" command configuration section look for the "ip helper address"  command - this will allow you to specify the target IP address to send DHCP requests to.  Depending on the size of your network, I'd probably trunk all vlan's back to one routing switch, and configure that routing switch for the IP helper configuration.

This is assuming that routing between VLAN's is configured on the ICX switch, and that the clients and server are permitted to communicate.





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Eric Markow

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You should use an RG Nets rXg. It can be configured with hundreds (or thousands) of DHCP servers on thousands of VLANs in just a few clicks, plus it has far more functionality than just DHCP. rgnets.com or sonoranet.com (distribution). 
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