Ambient Weather Weatherbridge SFTP Problem

[reifheck]

Hi.

Not sure if this is right place for this.

I'm using the Ambient Weather Weatherbridge (Meteobridge) to SFTP a file to my web server.

The firmware is updated to Meteobridge 6.4 (Sep 19 2026, build 15721), FW 1.4

When I tried to test uploads with Meteobridge using SFTP, I got the following errors:
Error: SFTP test upload failed: Couldn't read packet: Connection reset by peer
Error: Proxy-SFTP test upload failed: Error: SFTP connect to aurora.anaxanet.com via port 22 failed.

I looked at the logs in Meteobridge and didn't see any errors.

The Web Host sent me the following log of this error on their server.

Hello Reif,

So, my theory about the old, outdated client and TLS/cipher suite issue appears to be correct.

[2026-10-13 20:13:10]:CONNECT [108132] - [71.218.28.0]: - Incoming connection request on SSH SFTP listener 2 at 10.8.245.100:22 accepted from 71.218.28.0:38873
[2026-10-13 20:13:10]: INFO [108132] - [71.218.28.0]: - Client Identification: SSH-2.0-dropbear_2011.54
[2026-10-13 20:13:10]: ERROR [108132] - [71.218.28.0]: - No common KEX: [S: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,curve25519-sha256,curve25519-sha256@libssh.org,curve448-sha512,curve448-sha512@libssh.org,diffie-hellman-group18-sha512,diffie-hellman-group16-sha512,diffie-hellman-group14-sha256,kex-strict-s-v00@openssh.com] [C: diffie-hellman-group1-sha1,diffie-hellman-group14-sha1]
[2026-10-13 20:13:10]: ERROR [108132] - [71.218.28.0]: - Key exchange failed: Could not agree on key exchange parameters
[2026-10-13 20:13:10]:CONNECT [108132] - [71.218.28.0]: - Closing connection. Reason code : 3
[2026-10-13 20:13:10]:CONNECT [108132] - [71.218.28.0]: - Connection terminated
It is running dropbear, an SFTP implementation that is extremely hold (back in like 2010-2011 old). This is the cause, an outdated SFTP client.

Our server is requesting...

ecdh-sha2-nistp256
ecdh-sha2-nistp384
ecdh-sha2-nistp521
diffie-hellman-group-exchange-sha256
curve25519-sha256
curve25519-sha256@libssh.org
curve448-sha512
curve448-sha512@libssh.org
diffie-hellman-group18-sha512
diffie-hellman-group16-sha512
diffie-hellman-group14-sha256
One of these ciphers, but your client is saying "Great... I can do..."

diffie-hellman-group1-sha1
diffie-hellman-group14-sha1
They cannot agree, so the connection gets dropped. These 2 ciphers are extremely weak, group1 is from the early 2000s and group14-sha1 is from around 2007 era. The only fix here, is a newer SFTP client with modern cipher support.


They then created a work around and don't know how long the fix will work

It started working and they sent me the log with the fix:
Hello Reif,

[2026-10-13 21:12:12]:CONNECT [108283] - [71.218.28.0]: - Incoming connection request on SSH SFTP listener 2 at 10.8.245.100:22 accepted from 71.218.28.0:47611
[2026-10-13 21:12:12]: INFO [108283] - [71.218.28.0]: - Client Identification: SSH-2.0-dropbear_2011.54
[2026-10-13 21:12:12]:CONNECT [108283] - [71.218.28.0]: - Agreed upon KEX: 'diffie-hellman-group14-sha1' Host Key: 'ssh-rsa' C2S : 'aes128-ctr, hmac-sha1, none' S2C : 'aes128-ctr, hmac-sha1, none'
[2026-10-13 21:12:13]: INFO [108283] - [71.218.28.0]: - DH Key sizes: Server Public '2048', Client Public '2048'
[2026-10-13 21:12:14]:CONNECT [108283] - [71.218.28.0]: - Authenticating password for user 'uqkytoll_reifheck'
[2026-10-13 21:12:14]:CONNECT [108283] - [71.218.28.0]: - Native user 'uqkytoll_reifheck' authenticated
[2026-10-13 21:12:14]:CONNECT [108283] - [71.218.28.0]:uqkytoll_reifheck - Channel Open: 'session', Sender Channel: 0, Local Channel: 182144, Init Window Size: 24576, Max Packet Size: 32768
[2026-10-13 21:12:14]:CONNECT [108283] - [71.218.28.0]:uqkytoll_reifheck - Channel Request for 'subsystem : sftp', Sender Channel: 0, Local Channel: 182144, Reply: false
[2026-10-13 21:12:14]:COMMAND [108283] - [71.218.28.0]:uqkytoll_reifheck - Client SFTP version: 3
[2026-10-13 21:12:14]:COMMAND [108283] - [71.218.28.0]:uqkytoll_reifheck - Real Path for '.'
[2026-10-13 21:12:14]:COMMAND [108283] - [71.218.28.0]:uqkytoll_reifheck - Stat: /MBtags.php
[2026-10-13 21:12:14]:COMMAND [108283] - [71.218.28.0]:uqkytoll_reifheck - File open command received for '/MBtags.php' requesting WRITE,CREATE,TRUNC
[2026-10-13 21:12:14]: SYSTEM [108283] - [71.218.28.0]:uqkytoll_reifheck - File handle to '/MBtags.php' opened
[2026-10-13 21:12:14]: SYSTEM [108283] - [71.218.28.0]:uqkytoll_reifheck - Upload started for file 'C:\HostingSpaces\uqkytoll\westdenverweather.com\wwwroot\MBtags.php'
[2026-10-13 21:12:14]: SYSTEM [108283] - [71.218.28.0]:uqkytoll_reifheck - Successfully stored file at 'C:\HostingSpaces\uqkytoll\westdenverweather.com\wwwroot\MBtags.php' (46278 B received)
[2026-10-13 21:12:14]: SYSTEM [108283] - [71.218.28.0]:uqkytoll_reifheck - Handle '/MBtags.php' closed
[2026-10-13 21:12:14]:CONNECT [108283] - [71.218.28.0]:uqkytoll_reifheck - Received EOF for channel 182144, responding with EOF and close to sender channel 0
[2026-10-13 21:12:14]:CONNECT [108283] - [71.218.28.0]:uqkytoll_reifheck - Channel '182144' removed
[2026-10-13 21:12:14]:CONNECT [108283] - [71.218.28.0]:uqkytoll_reifheck - The client closed the connection
[2026-10-13 21:12:14]:CONNECT [108283] - [71.218.28.0]:uqkytoll_reifheck - Connection terminated
It did work, agreed on KEX diffie-hellman-group14-sha1, I cannot say this will last forever... because it is an older KEX and we try and balance newer modern ciphers with older ones, but not 20-year-old ones like diffie-hellman-group14-sha1. I would highly recommend getting with the developers of this and seeing if they can update the SFTP client to a modern version. Dropbear is still very actively developed, latest version is 2026.94 from July of this year. It does not have to be the very latest, 2013.62 supports curve25519-sha256@libssh.org, which we do support. So even a minor bump would help.

I also used Proxy-SFTP and it worked this time.

The Web Host sent me this log as well:
Hello Reif,

[2026-10-13 22:38:41]:CONNECT [108491] - [71.218.28.0]: - Incoming connection request on SSH SFTP listener 2 at 10.8.245.100:22 accepted from 71.218.28.0:48765
[2026-10-13 22:38:41]: INFO [108491] - [71.218.28.0]: - Client Identification: SSH-2.0-dropbear_2011.54
[2026-10-13 22:38:41]:CONNECT [108491] - [71.218.28.0]: - Agreed upon KEX: 'diffie-hellman-group14-sha1' Host Key: 'ssh-rsa' C2S : 'aes128-ctr, hmac-sha1, none' S2C : 'aes128-ctr, hmac-sha1, none'
[2026-10-13 22:38:43]: INFO [108491] - [71.218.28.0]: - DH Key sizes: Server Public '2048', Client Public '2048'
[2026-10-13 22:38:44]:CONNECT [108491] - [71.218.28.0]: - Authenticating password for user 'uqkytoll_reifheck'
[2026-10-13 22:38:44]:CONNECT [108491] - [71.218.28.0]: - Native user 'uqkytoll_reifheck' authenticated
[2026-10-13 22:38:44]:CONNECT [108491] - [71.218.28.0]:uqkytoll_reifheck - Channel Open: 'session', Sender Channel: 0, Local Channel: 182480, Init Window Size: 24576, Max Packet Size: 32768
[2026-10-13 22:38:44]:CONNECT [108491] - [71.218.28.0]:uqkytoll_reifheck - Channel Request for 'subsystem : sftp', Sender Channel: 0, Local Channel: 182480, Reply: false
[2026-10-13 22:38:44]:COMMAND [108491] - [71.218.28.0]:uqkytoll_reifheck - Client SFTP version: 3
[2026-10-13 22:38:44]:COMMAND [108491] - [71.218.28.0]:uqkytoll_reifheck - Real Path for '.'
[2026-10-13 22:38:44]:COMMAND [108491] - [71.218.28.0]:uqkytoll_reifheck - Stat: /MBtags.php
[2026-10-13 22:38:44]:COMMAND [108491] - [71.218.28.0]:uqkytoll_reifheck - File open command received for '/MBtags.php' requesting WRITE,CREATE,TRUNC
[2026-10-13 22:38:44]: SYSTEM [108491] - [71.218.28.0]:uqkytoll_reifheck - File handle to '/MBtags.php' opened
[2026-10-13 22:38:44]: SYSTEM [108491] - [71.218.28.0]:uqkytoll_reifheck - Upload started for file 'C:\HostingSpaces\uqkytoll\westdenverweather.com\wwwroot\MBtags.php'
[2026-10-13 22:38:44]: SYSTEM [108491] - [71.218.28.0]:uqkytoll_reifheck - Successfully stored file at 'C:\HostingSpaces\uqkytoll\westdenverweather.com\wwwroot\MBtags.php' (46300 B received)
[2026-10-13 22:38:44]: SYSTEM [108491] - [71.218.28.0]:uqkytoll_reifheck - Handle '/MBtags.php' closed
[2026-10-13 22:38:44]:CONNECT [108491] - [71.218.28.0]:uqkytoll_reifheck - Received EOF for channel 182480, responding with EOF and close to sender channel 0
[2026-10-13 22:38:44]:CONNECT [108491] - [71.218.28.0]:uqkytoll_reifheck - Channel '182480' removed
[2026-10-13 22:38:44]:CONNECT [108491] - [71.218.28.0]:uqkytoll_reifheck - The client closed the connection
[2026-10-13 22:38:44]:CONNECT [108491] - [71.218.28.0]:uqkytoll_reifheck - Connection terminated
Still using the older diffie-hellman-group14-sha1 KEX as well, so it would need to be modernized as well.


Is there anything the developer can do to fix this?

Thank you,
Reif Heck

[Mattk]

SFTP has become a nightmare. The Pro has been replaced by the Pro2 with a new OS. The following comes from the following on why a next gen PRO https://www.meteobridge.com/wiki/index. ... ridge_PRO2

Better Operating System.
Meteobridge PRO2 comes with OpenWRT 21.02.3 which solves a lot of SSL related issues of the previous model. SFTP and SSH issues can now take a rest. Furthermore WPA3 and up to date SMB protocols are supported.

[reifheck]

Thank you Mattk.

What about Ambient Weather Weatherbridge?

That is the device I am asking about.

Thanks again,

Reif Heck

[Mattk]

I believe they are identical at the SFTP level? Boris could confirm this?

Actually right now I have the exact same issue on a MBPRO (Red) that has worked fine for years, old SFTP server/setup works fine with the latest firmware, replacing the old SFTP server with a new version/new server/new crednetials etc and everything falls in a heap with the exact same error message you are seeing.

[reifheck]

Hi Mattk.

Is Boris the developer?

Do you think he can fix the firmware in the Ambient Weather Weatherbridge (Meteobridge)?

Thank you very much Mattk!

Reif Heck

[Mattk]

Yes Boris is the man and hopefully he will pick this up and confirm as I want to know also

No I don't believe so as that is why the PRO2 came into existence, things get old, outdated, components no longer available etc and can't be simply brought up to the ever changing requirements by firmware alone?

[reifheck]

Thanks Mattk.

That's too bad

I like this device and have only had it for about 2 weeks.

Please keep me up to date with what Boris finds.

Thanks again Mattk,

Reif

[Mattk]

Maybe Ambient needs to comer up to date as the PRO2 essentially superseded the original PRO around 2022 but many users don't get too in depth with SFTP. The original PRO is still supported within it's design and in reality it has been the SFTP server updates/changes that have created this issue. SFTP servers became EOL, no longer uneatable, it becomes a tight circle.

[admin]

SFTP on the TP-LInk 3020 which is pre-licensed sold by ambient weather does have a rather limited and also old OPENWRT underneath that does not support modern cypher and encryption standards. There is nothing that can be done, because newer better OS version and newer OPENSSL crypto libs will not fit into those tiny MR3020 devices (32 MB RAM, 4 MB Flash, that is all those units provide).

To get this solved, you can use the proxy-sftp service of your Meteobridge. It mainly pushes the payload via HTTPS to the Meteobridge server, which than does the SFTP upload and the server of course has all the newest fancy whistles turned on to make the security staff at your provider happy.
Therefore, proxy-ftp is the upload format you should use.