SG 300 seems to be preventing Windows systems from get an IP via Windows server DHCP

aperez004 · ‎02-16-2015

All the basics from the server are working and have been for years. I would appreciate not being asked to check the basics as "is the DHCP server registered".

There seems to be an issue where the VLAN is preventing DHCP from working. I have also read that MAC addresses don't get registered until there is a write. The issue also seems to roam. It affects different PC's at different times. I had this issue with this switch approximately a year ago.

Can I at least get some direction until I can post the firmware version and config. Its a busy small business and this issue is extremely unpredictable.

Thank you

Michal Bruncko · ‎02-17-2015

Hi

check if you have DHCP snooping disabled (at least try to turn it off and see if it helps)
check if you are running Rapid version of STP protocol
check if all ports toward end-user devices are configured as spanning-tree portfast ports. if you are not use portfast, your port transition to forwarding state could takes longer time resulted that all DHCP discover packets from client will be just dropped on switchport site until port transits to forwarding state.