Ecobee thermostat can’t connect to servers

ezhawk

@stephenw10
well, that didn't take long. once again, behind the pfsense my ecobee now shows disconnected. Network connectivity is all up. I can ping out from the ecobee by ip and dns name, but the pfsense is blocking its connection to the ecobee.com servers.

Gertjan

@ezhawk said in Ecobee thermostat can’t connect to servers:

but the pfsense is blocking its connection to the ecobee.com servers.

Blocking : what pfSense rule blocks traffic from the bee ?
Can you list the firewall rules on that LAN ?
Is the bee set up to use DHCP ? If so : read How to change Kea DHCP log level so now you know how to log DHCP leases : and the question is : did it get a DHCP lease (that is an IP, a network, a gateway, a DNS - check these all) ?
If static : what is it's setup ?

stephenw10

Mmm, what connection is actually being blocked?

If you kill all the states from the thermostat and allow it to open new states does that fix the connection? If not do any of those states have one way traffic with no replies?

GPz1100

Under steady state conditions I show the ecobee premium connecting to a single ip.

and periodic connections to the dns server (x.y.100.2).

Using any packages that may be doing traffic inspection?

ezhawk

@stephenw10

I've killed all the states and the connection doesn't restore. I reboot the ecobee and after letting everything come up clear out these are what i'm left with for states and the ecobee cannot connect to the ecobee servers.

(I had this exact same issue with Google Nest and assumed it was something with Nest which is why I now have an ecobee.)

stephenw10

Hmm, OK so two way traffic but both state sets are in FIN-WAIT rather than established and only 4 packets.

Try pcapping that traffic and see what's going on.

Interesting that it's the same remote address for both of you.

Can you try routing that traffic over a VPN to get a completely different source IP?

ezhawk

@stephenw10

I did pcaps from the WAN and LAN and rebooted the ecobee each time but not sure exactly what i'd be looking for in the pcap. I don't have a VPN to route traffic over.

stephenw10

I'm away right now so I can't setup a drop-link. But do the captures show just the 4 packets shown in the state table for each connection?

ezhawk

@stephenw10
i see some fin acks both ways. after a while all the states drop and then it comes back and in the states it just sits at fin wait.

stephenw10

Can we see the pcap from the pfSense gui with the TCP flags? You can obscure the IPs if you need.

We need to see which side stops responding.

ezhawk

@stephenw10

wan pcap

lan pcap

stephenw10

Hmm, interesting. That dupe ACK is odd. Like the server expects to see something from the client and doesn't. Except the dupe comes 12 microseconds after the first. Other than that it looks like a pretty normal TCP connection. The client just isn't sending or pulling anything. I do note there are no large packets shown. But they are not present on either interface. pfSense seems to be passing that traffic as expected.
Even when the dupe ACK doesn't happen the server sends a fin-ack pretty much immediately.

GPz1100

@ezhawk re vpn

You can set up a free cloudflare warp wireguard connection using this project - https://github.com/ViRb3/wgcf .

From the releases page download the one appropriate for your pfsense architecture (or a linux vm).

Run wgcf register then wgcf generate

This will create a .conf file from which you can pull the necessary credentials to supply pf's wg package. Use policy based routing to pass ecobee traffic through the cf tunnel. Don't forget to create an outbound nat rule.

GPz1100

@stephenw10 It would be interesting to compare the state timeout values between pfsense and the other firewall @ezhawk is using. Possible some values are longer in pfsense and/or not playing nicely with the isp?

Looking at the pfs/system_advanced_firewall.php page, all mine are default. WAN MTU at 1500 too (att fiber connection).

ezhawk

@GPz1100
mine are all default in the firewall settings too. WAN mtu is actually just using the adaptors default. Don't have any defined MTU.

stephenw10

@GPz1100 Are you able to grab a pcap for comparison with a working connection?

GPz1100

@stephenw10 What specifically do you want captured, and for how long? I can use the pf packet capture gui option but what options do you want set there?

The ecobee is on the IOT vlan which only has rfc1918 access to dns server and internet.

GPz1100

@ezhawk said in Ecobee thermostat can’t connect to servers:

@GPz1100
mine are all default in the firewall settings too. WAN mtu is actually just using the adaptors default. Don't have any defined MTU.

I understand, but since it is working with the other firewall, there must be some difference, no?

stephenw10

Just a typical TCP stream from the client to the server. Is it sending/receiving large packets every connection for example? Does the connection just remain open?

GPz1100

@stephenw10 Attached is a sanitized pcap. Ecobee mac and lan interace mac sanitized to begin with bb dd cc and lan mac begins with 11 22 33.

sanitizedpacketcapture--20250828135527.pcap

The capture is a 10 min segment of steady state operation.

Note, the ecobee tries to resolve api.amazon.com every 50s. This is denied via dns server as well as blocking the entire amazon asn for the ecobee ip.

Hope this helps.

PS. please delete the previous message - it's already tagged as deleted, please remove permanently.