DHCP Snooping Setup
Posted: 13 Nov 2025 03:44
Dear Team.
I am stuck in DHCP snooping scenario. As i use to enable DHCP-Snooping on the switches, the PABX stops to give ip addresses to the IP phones.
PABX is connected with Server farm switch with VLAN 20 for voice. I enabled VLAN base DHCP-snooping on this switch and trusted the port on which the PABX is connected (1/1/10). Configuration on server switch for DHCP-Snooping as per below:
vlan 20 members port 1/1/10 untagged
dhcp-snooping vlan 20 admin-state enable
dhcp-snooping binding admin-state disable
dhcp-snooping linkagg 1 trust
Core Switch Configuration:
dhcp-snooping vlan 20 admin-state enable
dhcp-snooping binding admin-state disable
dhcp-snooping linkagg 1 trust \\connected to server switch
Distribution Switch Configuration
dhcp-snooping vlan 20 admin-state enable
dhcp-snooping binding admin-state disable
dhcp-snooping linkagg 1 trust \\connected to Core switch switch
Access Switch Configuration
dhcp-snooping vlan 20 admin-state enable
dhcp-snooping binding admin-state disable
dhcp-snooping linkagg 1 trust \\connected to Distribution switch switch
Guide me where i did mistake in the configuration or how can i more secure the LAN network with L2 DCHP-Snooping configuration.
PABX (1/1/20) --- Server Switch (0/1) --- Core Switch (0/1) Distribution Switch --- (0/1) Access switch (1/1/1 -10) Ip Phones
I had attached the diagram for your further reference so it would be easy for you guys to give me a suitable solution.
I am stuck in DHCP snooping scenario. As i use to enable DHCP-Snooping on the switches, the PABX stops to give ip addresses to the IP phones.
PABX is connected with Server farm switch with VLAN 20 for voice. I enabled VLAN base DHCP-snooping on this switch and trusted the port on which the PABX is connected (1/1/10). Configuration on server switch for DHCP-Snooping as per below:
vlan 20 members port 1/1/10 untagged
dhcp-snooping vlan 20 admin-state enable
dhcp-snooping binding admin-state disable
dhcp-snooping linkagg 1 trust
Core Switch Configuration:
dhcp-snooping vlan 20 admin-state enable
dhcp-snooping binding admin-state disable
dhcp-snooping linkagg 1 trust \\connected to server switch
Distribution Switch Configuration
dhcp-snooping vlan 20 admin-state enable
dhcp-snooping binding admin-state disable
dhcp-snooping linkagg 1 trust \\connected to Core switch switch
Access Switch Configuration
dhcp-snooping vlan 20 admin-state enable
dhcp-snooping binding admin-state disable
dhcp-snooping linkagg 1 trust \\connected to Distribution switch switch
Guide me where i did mistake in the configuration or how can i more secure the LAN network with L2 DCHP-Snooping configuration.
PABX (1/1/20) --- Server Switch (0/1) --- Core Switch (0/1) Distribution Switch --- (0/1) Access switch (1/1/1 -10) Ip Phones
I had attached the diagram for your further reference so it would be easy for you guys to give me a suitable solution.