Out of the box switch and DHCP settings

[francktls]

Dear Community,

Got a question for switches in the following architecture.

Got a router with 2 tagged VLANs, if I want to install a Meraki switch without any configuration (dynamic IP as out of box) can I know the following beahavior : Switch tries to get an IP address on native vlan first.

My question is  : Is the switch tries also to get an IP address on any tagged VLAN automatically ?

Many thanks & best regards,

Franck.

[MerakiDave · Accepted solution]

Hi Franck, Meraki devices can be pretty "crafty" and persistent about how they attempt to establish connectivity, and you should comfirm with Meraki Support, but I believe the answer is yes, the switch will actively try to grab a DHCP address across any/all VLANs if it doesn't see any DHCPOFFER frames coming from the Native VLAN (which it'll always try first) it will attempt others.  So if you're drop-shipping new switches out of the box to remote locations (where there are Native VLANs other that VLAN 1) and you want to just be able to have someone cable them up and work, you should be ok, but again double check the exact bootup process with Support to be sure.

[PhilipDAth]

@MerakiDave is correct.  I think it also logs a warning/error somewhere if it ends up using an IP address on a VLAN other than the one configured.  I can't quite remember, but I think the device shows up in a warning state in the dashboard.

[francktls]

Many many thanks guys, that's what I though about the behavior.

Many thanks & best regards,
Franck.

[MRCUR]

Crafty is right @MerakiDave! Sometimes they're so crafty they end up on non-native VLAN's just to mess with you. 

[francktls]

Many Thanks @MerakiDave, 

For your information, I configured today a MX LAN4 ports with tagged VLAN 10 & 20, all untagged traffic dropped.VLAN & LAN4 interface Config on MX

DHCP config on MX

Finally MS got it's IP in tagged VLAN 10

DHCP scope status on MX

 Finally, the MS got an IP because the device is really crafty 😉 This is nice and almost rare behavior in the industry. It's gonna be decisive factor for some of our customers !!!

Good job guys, love your products *thumbs up*