andyvolk

Yes. VLAN settings are present on both sides. VLAN Settings on all Zyxel's is similiar to screenshot I posted before: First port is root port and all VLANs is tagged. Other ports are untagged with different VLAN PVID. All others works OK, but Zyxels not. New topology? If you mean that i posted before, where i want to…

I also tried to set DHCP server with clear config directly before looped Zyxel, exclude other devices (Pure mikrotik device with DHCP server and Zyxel switch), and still no receive any address, and no any DHCP traffic too.

Hi. Currently, i can't do wireshark on switch because all ports on them used and are in production. i try setup additional Mikrotik before problematic Zyxel, and grab traffic from it. In this setup DHCP traffic from Zyxel is missing. Devices behind Zyxel works OK. Need to notice, that trouble is on two offices, and two…

Ok. I need some time for Wireshark. Once I get access to the devices I will try to grab the traffic.

FD:7C is SIP phone, which was at wrong VLAN and can't receive IP. I fixed it. 0D:E5 is Mikrotik 4011 interface, which answer DHCP requests

@Zyxel_Melen, Here are screenshots: Green rectangle - is Zyxel which work OK renew ip address. Red rectangle - Zyxels which haven't ip address. Marked rows - is Zyxels Second screenshot is same zyxel from green rectangle at first screenshot, after manually reboot from web interface. @PeterUK , i will try to wireshark DHCP…

I do not have topology of this network (it so large), but have topology from similiar network. That topology is smaller, but have same issues with DHCP client. Blue lines - fiber link greed lines - tagged vlans ethernet link black lines - simple link Last time DHCP issue was at Zyxels marked 1,2,3,4

Here is my DHCP on Mikrotik Also i forget to say, that also on zyxels (and whole network we use VLANs). Settings GS1200 likes this (1 port is uplink to top level switch): Maybe it is important to reproduce issue. Currenly stats in network for zyxels: Total 29 items, 10 of them not receive DHCP address, 9 from 10 are…

This problem appears after some time, and not immediately. If you can please try to build a setup with 3-4 GS1200 with RouteOS 7 and leave it for a week for example. When I power off and then power on shitch all works fine for some times. But then lease not receive.

I write to Microtik support too, but think problem is from Zyxel side. Other devices work ok, and some zyxel switch too. After power off/on switch receive address, but after some times (3 days - 1 week) issue appears again. Fimware was before V2.00(ABME.1)C0 or older, and works ok. Here's full screen from mikrotik log