That can be, as well there is an option 'local routing' on the AP which may allow that traffic. You can try to turn that off. It's (Instant!) under System, then Advanced:
If clients have IP addresses in a VLAN that's 'known' to the AP, the client may be placed in there as part of the L3 roaming feature.
Packet captures may confirm this assumption.
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Herman Robers
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If you have urgent issues, always contact your HPE Aruba Networking partner, distributor, or Aruba TAC Support. Check
https://www.arubanetworks.com/support-services/contact-support/ for how to contact HPE Aruba Networking TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or HPE Aruba Networking.
In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
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Original Message:
Sent: May 07, 2025 10:07 AM
From: Notknown
Subject: No VLAN configured, yet Clients can still connect to SSID?
Thats the fun Part, since then until now, there have been more connections happening, and three of them were successful, two other attempted connections supposedly failed due to not reaching the DHCP or a Key Exchange (Mic failure?) Issue.
may it be that the previous three connections still had an IP lease from our Server and thus just bypassed the VLAN Tag in some way? It doesnt sound like it would make sense, but considering some work and two dont, thats the only idea i have right now.
Original Message:
Sent: May 07, 2025 09:59 AM
From: Herman Robers
Subject: No VLAN configured, yet Clients can still connect to SSID?
If you configure an SSID with a VLAN id that doesn't exist on the uplink ports of the switch, the client can probably connect to the SSID, but would not get an IP address or be able to go anywhere as the traffic is sent to the switch tagged with VLAN 25, then dropped by the switch.
------------------------------
Herman Robers
------------------------
If you have urgent issues, always contact your HPE Aruba Networking partner, distributor, or Aruba TAC Support. Check https://www.arubanetworks.com/support-services/contact-support/ for how to contact HPE Aruba Networking TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or HPE Aruba Networking.
In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
Original Message:
Sent: May 07, 2025 06:19 AM
From: Notknown
Subject: No VLAN configured, yet Clients can still connect to SSID?
Hi, I'm pretty sure I'm missing something very simple here, but google didnt get me far.
i have currently two 2540 and one AP304 running in a lab setup, Central-Managed but posting here because it doesnt look like whatever is happening is due to Central configuration.
on the AP are two SSIDs in use, one internal on VLAN 25 and one Visitor (the one im testing) on VLAN 27. We technically dont need the Employee SSID on the AP currently, but i also didnt deem it necessary to remove it.
Both of the switches that connect the AP to the Internet only ever knew the VLANs 1, 27 and 100 (Management VLAN) and I never configured VLAN 25 in any way on them, but an hour ago a client successfully connected to the employee SSID running on VLAN 25 and i can't figure out how that happened over Central or the switches themselves.