MikroTik MNDP can shut down Cisco APs

Hi all,

We’ve just bumped into a bug/incompatibility/hidden-feature in MikroTik ROS and/or Cisco APs. In our case we were using Cisco 1131AG access points, but it probably affects most Cisco access points.

With CDP enabled on the Cisco side, and MNDP (or Neighbour Discovery) enabled on the interface the AP is plugged into, the AP shuts down as soon as it receives a MNDP packet, giving a “Not enough power” error (the front ring LED turns amber or red).

Obviously this doesn’t happen when there is a switch between the AP and the MT router, since the switch receives the CDP requests itself and doesn’t forward them on, but if you plug the AP directly into the router, the AP will shut down after a while.

Solution is to disable MNDP on the MikroTik side or CDP on the AP side.

RouterOS RuleZ :smiley:

p.s. should be posted on Cisco forum in ‘Bugs’ section? =)

That doesn’t exist… Cisco gear never has no bugs… ever ever.. that’s what Cisco says so it must be true. :confused:

Sure they do. And they fix them, if you give them reliable and reproducible debug information.

Can you post the RouterOS version, and the IOS version? We don’t have 1130s but we do have a lot of Cisco APs (1230/1240/1250), and we’re about to deploy more RouterOS devices. I’d like to check our hardware and will file a TAC if I can get the same result.

RB450 running RouterOS v3.15
Cisco AIR-AP1131AG-E-K9 running IOS c1130-k9w7-tar.123-8.JA

The setup is Cisco AP ↔ 802.3af PoE injector ↔ Ether5 (in Bridge1) on RB450

Power Settings: Power Negotiation
Power Injector: [TICK] Installed on Port with MAC address XXXX;XXXX;XXXX (Switch MAC address)

Neighbour Discovery is enabled on Bridge1 and Ether5.
Disabling Neighbour Discovery on both Bridge1 and Ether5 lets the AP boot correctly

Wow,
there are BUGS on CISCO IOS, that’s why for that purpose, cisco for registered users have service called BUG TOOL where you can find BUG related to your, and the IOS version when it was solved. Because of bugs Cisco is bringing on versions of IOS-es same as RouterOS does.

Regard.

Faton