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Forum Discussion
GS110TP - DHCP Issue - Obtaining IP not possible
Hi everyone,
I have an issue with my GS110TP when trying to obtain an IP from DHCP.
This issue I already dicussed here, but as I noticed it was not already solved. It seems to be an issue of the firmware.
Original Post:
Again:
I have an AP from Ubiquiti which is connected to the GS110TP and is powered via PoE.
The GS110TP is connected vie Link aggregation trunk to an GS750E and in the GS750E the Ubiquity USG with DHCP server is plugged in.
When I try to obtain a IP with my smartphone, the process stucks at "Obtaining IP". This is because the ethernet packets for requesting an IP ist not forwarded from GS110TP to the trunk. This is what I saw when wiresharking the Ports.
This is only happening for untagged traffic.
I also have a tagged LAN. For the tagged LAN, the DHCP packets are forwarded without issues!
When I just reboot the GS110TP, the DHCP is also working for untagged network for some hours! But at a certain point in time it is still not working.
Last time I resetted the device and thought the issue was gone, but it was not!
Can anyone tell me, how to get support from Netgear professionals for fixing this issue?
Thanks in advance,
Harry
40 Replies
Hi Everyone,
anyone any idea or support for this topic?
My brother owns a GS110TPPv3 and also a GS750E (connected without LAG). He has other AP fron Ubiquity.
His router with DHCP-Server is directly connected to the GS110TPP (different to my setup)
But he has same issue that at a certain point in time the GS110TPP doesn't forward DHCP requests to the other port(s)!
Can please anyone give me an advice how to proceed?
I proofed via wireshark that this is an issue in netgear firmware!
Thanks and BR
Harry
Thanks for your feedback!
I opened a support ticket for my issue and related to this post.
Thanks and BR
Harry
Hi Harry,
Tried to reproduce the behavior by using software packet generator to inject both untagged and tagged DHCP request packets form more than five hours but in vain, not sure if the time is long enough, do you know how long will the behavior presents after reset of reload? And if it is possible to provide untagged and tagged DHCP request packets for further test?
Furthermore, what is the behavior of the device regarding to DHCP offer packets? Will the device withdraw DHCP offer packets?Hi Harry,
Sorry, there was a mistake in my previous post, it should be "DHCP Discover" packets, not "DHCP offer" packets.In addition, would you please help to provide the information below as well for further analysis?
1. Configuration file of GS110TP.
2. Address-table when the issue presents.
3. MAC address(es) of the Ubiquiti device interface(s) that connected to GS110TP.
4. DHCP configuration of Ubiquiti device, especially pool and lease time.Thanks for considering my request.
Hi Byrolin,
thanks for your attention to my issue.
I try to answer your questions - if I forget something, please give me a hint.
Just another important information I detected while actually testing again:
When a new Client, which was not active for a longer time, connects the AP it will get an IP Address!
But on same time, a client which was connected and active to one of the other APs, the device stucks in the loop "Obtaining IP" ... " Disconnected" ... "Obtaining IP" ... "Diconnected" ...
And this is what I have seen in Wireshark, that the DHCP Discover of this device is not forwarded to the correct port from GS110TP.
After I changed (randomized) the MAC of the client which stucked in the loop, the client connects within the next second without any further issues.
So in my opinion, there seems to be something wrong with MAC-cache or something similar - without knowing much how the device is working!
Thanks in advance!
Harry
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