Allied Telesis Rapier i Series - Manual (Page 22)

Page 22 | AlliedWare™ OS How To Note: DHCP Snooping on Rapier-style switches
Troubleshooting
Increasing the port’s maximum leases will permit multiple clients per port.
Switch is dropping ARPs
If you have DHCP snooping in ARP security mode, then unknown clients on untrusted ports
will not be able to ARP.
Known clients on untrusted ports will be able to ARP.
A client is known on an untrusted port if it has an IP/MAC entry in the DHCP snooping
database (show dhcpsnooping database). Your DHCP server must be on a trusted port.
Manager > set dhcpsnooping port=3 maxleases=2
Info (1137260): DHCP Snooping port(s) 3 updated successfully.
DHCPSN_ARP: [0193a9ec] ARP Received on untrusted port 24 VLAN 1
DHCPSN_ARP: [0193a9ec] ARP Discarded, sender not found in DHCP Snoop DB
DHCPSN_ARP: [01a6f5ec] ARP Received on untrusted port 1 VLAN 1
DHCPSN_ARP: [01a6f5ec] ARP to be forwarded, sender validated
DHCPSN_ARP: [01a6f5ec] Forwarding ARP at L2 for VLAN 1
DHCPSN_ARP: [01a6f5ec] Forward ports (except 1)
DHCPSN_ARP: [01a6f5ec] Tagged:None
DHCPSN_ARP: [01a6f5ec] Untagged:24
Manager > set dhcpsnooping port=24 trusted=yes
Info (1137260): DHCP Snooping port(s) 24 updated successfully.
Manager >
DHCPSN_ARP: [023a218c] ARP Received on trusted port 24 VLAN 1
DHCPSN_ARP: [023a218c] Forwarding ARP at L2 for VLAN 1
DHCPSN_ARP: [023a218c] Forward ports (except 24)
DHCPSN_ARP: [023a218c] Tagged:None
DHCPSN_ARP: [023a218c] Untagged:1