topic Re: show ip dhcp-snooping binding summary is blank in ExtremeSwitching (VSP/Fabric Engine)

show ip dhcp-snooping binding summary is blank

MaxHibbin — Tue, 11 Feb 2025 17:19:40 GMT

I don't know how to get this command to populate any information. We are using 5320's on VOSS 9.0.3.0. DHCP Snooping says its enabled and the ports all say untrusted. I have clients connected but table is blank. What am I missing? Thanks so much.

Re: show ip dhcp-snooping binding summary is blank

EF — Sat, 15 Feb 2025 20:15:45 GMT

did you enbale it at interface vlan level?

How To: VSP: How to Configure DHCP Snooping | Extreme Portal

Re: show ip dhcp-snooping binding summary is blank

MaxHibbin — Fri, 21 Feb 2025 21:27:52 GMT

Thanks for the reply.... well, no I don't think I have enabled it on int vlans, but is that a requirement for it to work on a gigabit ethernet interfaces? I certainly don't have interface vlans on every switch for every client IP network, so not exactly sure what you are getting at. More than the security feature itself I want to see from the switch what IP addresses all my clients have.

Re: show ip dhcp-snooping binding summary is blank

EF — Mon, 24 Feb 2025 07:05:23 GMT

Hi Max,

I belevibe is mandatory enable at level interface to work.

interface vlan <vlan#>
ip dhcp-snooping enable
exit

This not meaning that you must have IP address on it y every SW of the net.

Try it.

Re: show ip dhcp-snooping binding summary is blank

MaxHibbin — Mon, 24 Feb 2025 20:07:28 GMT

Thank you. However what interface vlan are you suggesting? a certain vlan? a random vlan? all vlans? The other thing about our clients is they are receiving a dynamic isid/vlan assignment from a radius server. So a particular isid/vlan a client may be on is not known to the switch

Re: show ip dhcp-snooping binding summary is blank

EF — Wed, 26 Feb 2025 07:51:21 GMT

As is described in the kb How To: VSP: How to Configure DHCP Snooping | Extreme Portal you must enable per SW:

- globally
- define trust and untrusted ports (NNI are trusted by default)
- per vlan in which you want enable the funcionality

So if you have in BEB, example, VLAN 10 users and VLAN 20 APs, and you want see the user only:

int vlan 10
ip dhcp-snooping enable

About your enviroment in which the vlan/isid is asigned dynamically and the SW is aware of the vlan, sorry I dont have experience on it.

Regards

Re: show ip dhcp-snooping binding summary is blank

MaxHibbin — Thu, 27 Feb 2025 22:20:49 GMT

Thanks again, I think this gets to the bottom of it, the clients isid comes down as a elan thru radius and the sw doesn't have the vlan defined on it let alone an addressed int vlan. I guess it is not possible. I heard about a Node Alias feature in VOSS 9.1 perhaps that will serve the need here. Thanks again.