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hp switch with dhcp-snooping

I have several hp switches on my network, core is 5406 and edges are 2500 and 2600. At the core I have one dhcp server on port a1 for vlan 5, I have fiber links to edge switches. I need to trust my dhcp server to be abke to only dhcp server to hand out ipaddress. Do I need to implent dhcp snooping on both the edge abd core switch? What would command look like? Thank

Craig Beck

Yes, you configure the trusted port on the switch where the DHCP server is connected, and enable DHCP snooping on that switch, then just enable DHCP snooping on the access switches.

This is a great link...

http://integratingit.wordpress.com/2012/08/13/configuring-dhcp-snooping-on-hp-procurve-switches/

surbabu140977

In short, you have to enable it everywhere.

Craig Beck

...or just use the link I provided ;-)

officertango

ASKER

I am clear with all the commands except the trusted port part. Here is my scenario:

HP Core----DHCP server on Port A1
HP Core (port B1) connects to Hp Edge (port1)--- it is tagged between the switch, also on the edge there is a untagged port 2

command:
On the HP core:
dhcp-snooping trust A1, B1???
On the Hp Edge:
dhcp-snooping trust 1 or 2???

thanks

ASKER CERTIFIED SOLUTION

Craig Beck

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officertango

ASKER

On the core:
DHCP-snooping trust A1 (this i agree) how about the downlink port to the edge, port B1 to the edge switch, don't I need to trust this port also?

on the edge:
don't I need to put in "port 1" uplink to the edge?

thanks for helping

Craig Beck

Ok, downlink ports no - uplink ports yes. So you are correct, you will need to to it at the uplink port on the edge switch too.

officertango

ASKER

So the command will read as following for the TRUST part:

Core:
dhcp-snooping trust A1, B1

Edge:
dhcp-snooping trust 1

correct??

thanks

Craig Beck

Not quite...

Core:
dhcp-snooping trust A1

Edge:
dhcp-snooping trust 1

You don't need to trust the downlinks, just the uplinks, so the ports going towards the DHCP server.

Don't forget to enable dhcp-snooping for the required VLANs.

officertango

ASKER

Yes, I won't forget the VLAN.
When you refer to Downlink: to you saying from CORE to Edge?
Uplink: Edge to Core?

thanks a million

Craig Beck

Yes that's it :-)