Two Portable M4250 - Both need DHCP

[UMJonny]

Hello.

Two portable AV Racks. Some times they will be used together (fiber link via SFP) and some times they will be used in isolation. In both cases, however, i will need DHCP. Both switches are M4250.

Could i possible configure a different range (on the same subnet) for a pool on each switch? Then, some how prevent the DHCP traffic from moving across the switch link? That way the servers wouldn't step on each other.

I will have a QSYS core here as well, which i could script some SNMP control. If there is a way to enable or disable DHCP via SNMP that could work. I would have it monitor for both switches being online and make sure only one switch had the DHCP server on.

The only other thing i can think of is using some external DHCP server like an inexpensive router. Less elegant, but would work just fine.

Let me know what you think the best option is.

Thanks! 

[schumaku]

From the IT Web interface, disable resp enable the DHCP server service as required.

[UMJonny]

Thanks. I appreciate the response, but i'd like to understand a little more about what this is actually doing.

Can you refer to this in the manual or explain a little more?

Thanks!

[UMJonny]

Could i possible do this with DHCP snooping?

For example: configure a server and pools (different ranges) on each switch. Then, configure each switch with DHCP snooping that only trusted the Gig ports, and not the SFP? Then any DHCP requests from the SFP ports are dropped.

Thanks

[schumaku]

System > Services > DHCP Server > DHCP Server Configuration.

Somehing like this:

AV Line of Fully Managed Switches M4250 Series Software Administration Manual Firmware Version 13.0.... - Chapter 21, DHCP Server

[UMJonny]

Ah, so you're suggesting that i just enable and disable one of the DHCP servers as needed. Not an option, unless i can do that via SNMP.

This is somehting that needs to happen automatically without an admin or programmer around.

Would the DHCP snooping idea work?

Thanks