I have an issue with dhcp requests not reaching the client and therefore not getting an ip address.
I have a draytek 3900 router connected to a netgear M4100-50G-POE switch which connects to 3 draytek 910C access points via tagged vlans. There are 2 VLANs, vlan10 for main, vlan20 for guests. VLAN10 gets ip addresses from a windows dhcp server and vlan20 gets the ip address from the draytek 3900 router.
Any device on the guest wifi gets a valid ip address without fail.
The majority of time the devices on vlan10 gets a valid ip address through wireless but occassionally when it is busy in the office they fail to get an ip address but on the dhcp server i can see DHCPDISCOVER and DHCPOFFER but the device never sees the OFFER. Anything connected to the ethernet on vlan10 will 100% get a valid ip address.
As it appears to be an issue with only the VLAN tagged ports and i can see traffic to the dhcp on vlan10 i believe it is an issue with the netgear switch rather than the router or access points.
I have read posts about IGMP snooping but i don`t fully understand what is going on or if i should disable it.
It seems that some of your devices fails to acquire an IP from your DHCP server. May you be able to share a screenshot of the switch's configuration? So that we can further check what seems to be happening on your network. You may also try to disable IGMP snooping to check if that will work. Please upgrade the firmware to its latest version.
IGMP snooping helps to optimize multicast performance and is especially useful for bandwidth-intensive IP multicast applications such as online media streaming.
Sorry for the slow reply, the notification emails were getting quarantined so i didn`t receive them.
I`ll take a look at getting some screenshots on Monday.
One odd things is if i make the wifi network adapter on the laptop set to prefer 2.4Ghz it will then connect straight away and then i can reset it to no preference and it will work.
I`ll try and disable the IGMP snooping and see if this works.
