AP Mode "Attached Devices"

[Chuck_M]

My Orbi is in AP mode behind a pfSense firewall providing DHCP along with a piHole providing DNS.  Things seem to be working fine with one odd anomaly.

Of course in the AP mode, the menus in the Orbi webpage are limited.

One of the menu items that works is the "Attached Devices".   

My question is:  The IP addresses shown on the attached devices screen do not seem to match reality...  Has anyone else using a 971 in AP mode noticed this?  The IP addresses include 169.xx.xx.xx -- but those devices are assigned an IP (192.168.xx.xx) (and are working) within the network.

I am wondering if this behavior is due to the last assigned IP addresses when the 971 was in router mode?

My firmware is up to date on V9.12.4.16_1.3.21.

The main Orbi is found at 192.168.1.2 and the two satellites are at .4 & .5.

Thanks for any insight.

[CrimpOn · Accepted solution]

That depends on the pfSense box.

The BE971 router has

• WAN port rated to 10G.  If the pfSense has an Ethernet port capable of 2.5G, then the Orbi port will connect at 2.5G
• One LAN port rated to 10G.  If connected to the 2.5G switch, then it will also connect at 2.5G
• (4) 2.5G Ethernet ports. Any of these could be connected to the 2.5G switch.
  (only connect the 971 to the switch with one cable - your pick of port)

This router is about as future proofed as it could get.

[CrimpOn]

You are probably aware that IP addresses that begin with 169 are "Link Local" addresses

https://en.wikipedia.org/wiki/Link-local_address 

These are created by devices when they fail to get an IP assignment from a DHCP server.

There may be an issue with the pfSense DHCP server

[Chuck_M]

I am aware...  that's why I bring this up... everything is working fine, it is Orbi that has this list of attached devices, not pfSense.    I think Orbi in AP mode has not updated the IP addresses of those devices connected.

[CrimpOn]

Do these devices appear on Attached Devices with both IP addresses? The 169 that they created for themselves and also the 192.168  that pfSense assigned them?

How are the 971 router and 970 satellites connected?

[Chuck_M]

I have one satellite hard wired and one wireless.

Here is a partial screen capture of the Orbi Attached devices along side the Active DHCP listing from pfSense.   

I have circled and cross referenced devices... you can see that what the Orbi is showing is not agreeing with the DHCP server... but all devices work.

 

[CrimpOn]

Thanks for supplying information.  Perhaps a silly question: Has the entire Orbi system been powered off and back on again since it was converted from 'router' to 'access point' mode?  (If not, please do that.)

In terms of connections, could you please describe where the ports on each device are connected?  i.e.

• The WAN port on the router connects to ....?
• The LAN ports on the router connect to...?
• The 'wired' satellite LAN ports connect to...?

There have been numerous discussions on the forum concerning Orbi systems in AP mode with every Orbi device connected directly to a switch or firewall (and thus 'wired' satellites not appearing on one of the router LAN ports).

Did not see any devices on those lists with the 169 IP address.  Are those gone now?

[Chuck_M]

I will reboot - but I am certain it has been rebooted several times -- and also factory reset more times that I care to count.

The WAN port on the Network Appliance running PF Sense goes to the Cable Modem (Cox).  The cable modem is in bridged mode.

The LAN port on the Network Applicance running PF Sense goes to an unmanaged 2.5G switch.

The unmanaged switch connects to Orbi and other wired devices including an Orbi satellite.  The other Orbi Satellite is wireless backhaul.

There are three 169 devices (all cable tv boxes) showing on the list, they were just not on the screen cap.

The network appliance running PF Sense provides DHCP.

The Orbi is in Access Point Mode and only provides connectivity to wireless devices (and works well other than this display).

[CrimpOn]

Thanks for the information.  This description is similar to other discussions regarding Orbi products in AP mode.

• When the Orbi router WAN port is connected to the network (i.e. this 2.5G switch), and
• A satellite is also connected to the network (2.5G switch)
• But the satellite is not connected directly to one of the router LAN ports

This creates a situation where the Orbi router is not able to accurately display information about devices connected to the network.

Why "things work".  (Layer 2 Ethernet)

The reason devices connected to the network appear to function correctly is the Ethernet hardware Layer 2 routing tables present in every Ethernet switch.  Each Ethernet switch (on the Orbi router, the pfSense box, that 2.5G switch, the Orbi satellite, and every device connected to the network maintains an internal table that shows which port "leads to" every MAC address on the network.  Sending information to another device on the network involves these steps:

• Determine if the target IP address is in the LAN IP subnet (using the subnet mask)
• If the target is IP in the LAN, use the MAC address for that IP found in the ARP table.  (If it is not in the ARP table, issue an ARP request to learn the MAC address.)
• If the target IP is not in the LAN, use the MAC address of the IP Gateway device. (the pfSense Ethernet adapter).
• Look in the Ethernet tables for which Ethernet port leads to that MAC address.
  • Most user devices have a single network port, so the answer is "use the only port there is".
  • Switches, such as the Orbi router, Orbi satellite, pfSense box, and that 2.5G switch may have more than one Ethernet port.  Each has a table of MAC addresses that can be found out each port.  Look in the table and select the port that leads to that MAC address.
• Send the packet out that port.
• When it gets to the next device, that device will do the same thing.  "Which port leads to this MAC address?"

A large corporation or college campus may have hundreds of Ethernet switches.  Each of them may have a table of thousands of MAC addresses.  They have no concept of "where" devices are physically located.  They just know, "to get to this MAC address, send the pack out port xx".

Within a few seconds of a network powering up, every Ethernet switch on the network collects the MAC address of every packet it sees and which Ethernet port it came in on.  Ethernet broadcast packets, such as DHCP requests, ARP requests, etc. are broadcast packets.  They get forwarded out every port in the network.

However... (and this is a BIG however), although the Ethernet module on the Orbi router "knows" how to send a packet to any MAC address, information from Orbi satellites that "comes in" on the WAN port is not processed.  The router knows that the satellites are (a) connected via WiFi, or (b) connected to one of the router LAN ports.  Once that 'wired' satellite changes from WiFi to Ethernet connection, no information about Attached Devices reaches the router.

The only way to get the Orbi system to accurately describe Attached Devices is to have the 'wired' satellite appear to be connected to a LAN port (and not to the WAN port).

For example:

• Rather than connect the 2.5G switch to the pfSense box.  Connect the Orbi router to pfSense and connect the 2.5G switch to a router LAN port.
• Connect the remaining devices on the network to the 2.5G switch.

[Chuck_M]

This is really good info... for which I am very grateful for you taking the time!

FInal question before we put this to bed.

I have a 2.5gig connection via Cox.

If I connect Orbi directly to pfSense (The yellow WAN port?), and then the switch to a LAN port, will that preserve 2.5 gig throughput for all? 

Thanks again -- Chuck

[CrimpOn · Accepted solution]

That depends on the pfSense box.

The BE971 router has

• WAN port rated to 10G.  If the pfSense has an Ethernet port capable of 2.5G, then the Orbi port will connect at 2.5G
• One LAN port rated to 10G.  If connected to the 2.5G switch, then it will also connect at 2.5G
• (4) 2.5G Ethernet ports. Any of these could be connected to the 2.5G switch.
  (only connect the 971 to the switch with one cable - your pick of port)

This router is about as future proofed as it could get.

[Chuck_M]

This is the answer!  My pfSense box is 2.5 gig.

Thank you for taking the time to explain the finer details to me... greatly appreciate it -- hope to be able to return the favor one day.

Will let you know how it turns out and what the resultant behavior is.

Chuck

[Chuck_M]

I had exactly the same issue. 

What are you using for a router if the Orbi is in AP mode? 

What is providing DHCP? 

Check the ethernet wiring as described above...