I’ve recently installed a Mikrotik CRS-125 and a separate 2.4GHz AP in a home installation. The 2.4GHz AP is connected to the Mikrotik via an Ethernet cable. I have a wireless weather station connected to the 2.4GHz AP which uploads current weather conditions to cloud-based servers using HTTP GET packets. I have a RasPi connected to the Mikrotik via Ethernet which I’d like to use to capture the weather data and store in a sqlite database. Here is a summary of the setup:
Mikrotik CRS-125: 192.168.1.100
Wireless AP: 192.168.1.151 (connected to Mikrotik via Ethernet)
Weather Station: 192.168.1.179 (connected to Wireless AP via 802.11n)
RasPi Server: 192.168.1.162 (connected to Mikrotik via Ethernet)
I have a single bridge set up in RouterOS which bridges all ports on the router, including the wlan1 and wlan2 ports. I do not currently have any VLANs set up.
When I log into the Mikrotik and use the Packet Sniffer built into RouterOS I can see the outbound HTTP GET requests from the Weather Station to the cloud server. When I use Wireshark or tcpdump from the RasPi I can see the weather station sending broadcast UDP packets (255.255.255.255) to the local network but I can’t see the HTTP GET requests to the cloud servers. I can ping the Weather Station from the RasPi…I just can’t seem to get to the HTTP packets. I’m sure there is a simple process to access the weather station HTTP data, but haven’t been able to discern where to start looking to accomplish this. Can someone please point me in the right direction to get started?
Thank you,
Kurt
It is very normal that you do not “see” this traffic on the Raspberry Pi on a SWITCHED environment. (and a CRS is a switch)
Broadcasts still “flood” out of the ports, that is why you see them arriving at the Raspberry.
The Mikrotik does allow you to see this, since this is where everything comes together.
I’m not familiar with CRS, but you can fix this by using some sort of “port mirror” and DUPLICATE the packets from Weather station → CRS → Internet out of the port on which the Raspberry is connected.
Port Based Mirroring
The first configuration sets ether5 port as a mirror0 analyzer port for both ingress and egress mirroring, mirrored traffic will be sent to this port. Port based ingress and egress mirroring is enabled from ether6 port.
/interface ethernet switch
set ingress-mirror0=ether5 egress-mirror0=ether5
/interface ethernet switch port
set ether6 ingress-mirror-to=mirror0 egress-mirror-to=mirror0