GS1200 DHCP Client and Mikrotik Issue

Zyxel_Melen

Hi @andyvolk,

Need to notice, that trouble is on two offices, and two uses VLAN.
On other objects, which don't use VLANs there is no such problem.
Maybe it because VLAN.

May I know if this VLAN setting is on both GS1200 and Mikrotik router? Could you share the details with me? It would be great if you could provide the VLAN setting screenshot. Also, I would like to know if your new topology is Mikrotik router - - - GS1200?

andyvolk

https://community.zyxel.com/en/discussion/comment/62050#Comment_62050

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 isolate other - then, yes is mikrotik with clean config - and looped switch (it was in looped before i plug it in new topology)

Old topology is same as before:
First office: Mikrotik 4011 - about 2-3 CSS326 & 5-8 CRS326 - Zyxels. Total 29 items, 8 of them currentry not receive DHCP address, 4 of them more frequent loss address (pluged via 4011 - CRS326 - CRS326 - CRS326 - CSS326). Reboot all of them was 2 weeks ago. About 10-12 VLANs
Second office: Mikrotik 4011 - Zyxel 1200-8 (lost IP) - CRS106-1C-5S - Zyxels. Total 9 items. 4 of them currently not receive IP address (and they frequent lost address). 2 VLANs
Also present this scheme: Mikrotik 4011 - Zyxel 1200-8 (lost IP) - Zyxel 1200-8 (IP present). Interesting things, that root Zyxel loss IP, but behind, second Zyxel works OK.

Other offices: No VLANs. About 1-3 Zyxels per office. Works OK

Zyxel_Melen

Hi @andyvolk,

Thanks for the detailed information. I'm not sure if this issue is related to VLAN currently. But this issue seems related to option 50: (0.0.0.0). Once the switch receives NAK from the server, it should return to the DHCP initial status, which means it should send DHCP discovery. However, I cannot see this correct behavior from the shared packet.
To investigate deeply, could you share the device configuration file with me? I will send the required item in a private message.