DHCP Delay in GPON

[alihassan]

There is a Meraki network where the Calix GPON's OLT and ONU managed by a third-party vendor are in between my Meraki MX firewall and MR access points. The MR access point (AP) is connected to the ONU and powered by a power injector.

When Wi-Fi users roam from one to another place, especially when they come back to their rooms where the ONU and AP are located, they are affected by the "No Internet access" issue which I suspect could be something related to the DHCP failure or delay problem. After they turn off and on Wi-Fi back on their devices or the ONU rebooted, then only the user devices can obtain the valid IP address and have Internet access.

Has anyone experienced a similar issue where the Meraki AP is connected to the GPON's ONU, and what troubleshooting steps can be performed from the Meraki dashboard or GPON system in this case?

[cmr]

Where is the DHCP server?  Are you using bridge mode L2 roaming or L3 roaming?  When I last used a GPON system we had the ONUs dishing out addresses to the local clients.

[alihassan]

1. The DHCP server for wireless clients is in the Meraki MX firewall.
2. I am using bridge mode L2 roaming.

[PhilipDAth]

So you have:

Internet -> Meraki MX -> GPON -> Meraki MR
Have I understood correctly?

Are they MRs able to communicate with each other ok (you could test this by trying to get one to ping another)?  That is needed for layer 2 roaming.  I wonder if there is some kind of layer 2 isolation enabled.

[alihassan]

The network infra is as follows: Internet --> Meraki MX --> Meraki MS Core Switch --> GPON --> Meraki MR

For those APs in public areas that are directly connected to the Meraki MS switch (i.e., not running on GPON), they can ping each other. However, those in-room APs connected to the GPON ONU are not pingable.

[cmr]

Are the ONU connected MRs on the same subnet as the other MRs?

[alihassan]

The ONU is on a different subnet from the Meraki device subnet.

[cmr]

What is routing between the subnets?  Does it have any rules or policies?

[PhilipDAth]

> However, those in-room APs connected to the GPON ONU are not pingable.

Roaming may not work properly in this case if the APs can not talk to each other, to exchange roaming data.

You wont even be able to use normal layer 3 roaming.

The only way I can think of to resolve this is to also use an MX, and use layer 3 roaming with tunneling back to that MX.

https://documentation.meraki.com/MR/Client_Addressing_and_Bridging/SSID_Tunneling_and_Layer_3_Roamin...