MX75 PPoE Century Link Not connecting

[Bala1]

I have Century Link Fiber connection currently working fine on my existing router. When I try to configure the same on MX it is not connecting at all. Tried with or without VLAN 201 tagging, with and without centurylink.net in the username, factory resetting the MX nothing helps. I checked credentials it is correct one. Is it possible to connect the CL ethernet directly on Internet 2 port on MX? or do we need a CL modem in transparent mode to connect to their network. ? I hate to connect another device in between if possible. Let me know if I'm missing something.Thx

[Johnfnadez]

Hi!

Have you tried to configure the PPoE using the local management webpage? If you only have this uplink it’s probably config is not getting applied to avoid loose cloud connectivity 

https://documentation.meraki.com/General_Administration/Tools_and_Troubleshooting/Using_the_Cisco_Me...

[Bala1]

First I configured everything from internally so the config's are saved and then tried to connect the CL ISP directly to WAN 2 port. Didn't work so did a factory reset and tried local config. I will try that one more time and check.Just curious so if I do it from local PPoE wont work since it can't save the config?

[Brash · Accepted solution]

Never used CenturtyLink personally, but a few things it could be:

 - Some ISP's have sticky MAC address learning and will only allow 1 MAC address on the port. You may need to wait a few hours for it to forget the old router and accept the MX

 - It could be an MTU issue - I think their side should be configured for 1492 but don't quote me on that.

Either way you're best calling up CenturyLink to see what they are seeing on their side.

[Bala1]

CL support is not that great. I will try again when their support is available in my timezone again.

[Bala1]

Brash, You nailed it buddy. It was MTU plus VLAN tagging. I found an Meraki article to check MTU on my current setup and found CL accepts only 1492. I called Meraki support to change that on the WAN port, still didn't work as soon as I added VLAN 201 (CL VLAN tagging) it connected immediately. Thanks for your help

[PhilipDAth]

Looking at their setup guide:

https://www.centurylink.com/home/help/internet/modems-and-routers/advanced-setup/wan-settings.html 

It shows they support IPOE, which is a different name for DHCP.  This suggests you should be able to plug the MX WAN interface in with zero configuration.

You should expect to wait 5 minutes for the MX to come online for the first time.  You can monitor the local status page to see if it is working, or what the problem may be:

https://documentation.meraki.com/General_Administration/Tools_and_Troubleshooting/Using_the_Cisco_Me... 

[Bala1]

John and Philip. Thanks for your support.