I have set up a Ubuntu server that I plan on using to backup my macbook air using rsync. But every time I use rsync, or even scp, the connection drops, with one of the following errors:
packet_write_wait: Connection to 192.168.1.202: Broken pipe
packet_write_poll: Connection to 192.168.1.202: Broken pipe
packet_write_poll: Connection to 192.168.1.202: Protocol wrong type for socket
Now I have searched for other questions like this, and the usually people have this problem with long backups where the session times out. For me this always happens within 10 seconds of starting the file transfer. I get the same errors using scp and rsync. I guess it could be due to a faulty network connection, but I find it hard to believe that my connection to the server on the same LAN is that unstable. Anyone have any ideas?
Examples of the commands I have used that result in the errors:
scp -r /Users/Matt/Documents matt@192.168.1.202:/media/matt/MattsBackups/
/usr/local/bin/rsync -av -e ssh /Users/Matt/Documents matt@192.168.1.202:/media/matt/MattsBackups/
I did some more testing today, and strangely enough it was working fairly reliably from outside my LAN. So I tried again from inside my home network, and it still doesn't work.
Running
grep 'sshd' /var/log/auth.log
on the server shows the following error
fatal: ssh_dispatch_run_fatal: Connection from <My IP> port 49870: message authentication code incorrect
Some more detailed information on my setup:
Macbook Air OS X 10.11.5
OpenSSH_6.9p1, LibreSSL 2.1.8
rsync version 3.1.2 protocol version 31
Ubuntu Server
OpenSSH_7.2p2 Ubuntu-4ubuntu1, OpenSSL 1.0.2g-fips 1 Mar 2016
I did notice the difference in ssh versions but I was hoping it wouldn't be an issue. I can try and install a newer version with homebrew.
UPDATE:
OK I just updated ssh with homebrew to
OpenSSH_7.2p2, OpenSSL 1.0.2g 1 Mar 2016
which appears to be the same version used on the Ubuntu box. However, Rsync still results in the error when I run the command. Heres the command I tried with the ssh -v flag:
/usr/local/bin/rsync -a -e '/usr/local/bin/ssh -v -c aes128-ctr -m hmac-sha1' /Users/Matt/Documents matt@192.168.1.202:/media/matt/MattsBackups/
The output is:
OpenSSH_7.2p2, OpenSSL 1.0.2g 1 Mar 2016
debug1: Reading configuration data /usr/local/etc/ssh/ssh_config
debug1: Connecting to 192.168.1.202 [192.168.1.202] port 22.
debug1: Connection established.
debug1: identity file /Users/Matt/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/Matt/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/Matt/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/Matt/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/Matt/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/Matt/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/Matt/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /Users/Matt/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu1
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu1 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 192.168.1.202:22 as 'matt'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: aes128-ctr MAC: hmac-sha1 compression: none
debug1: kex: client->server cipher: aes128-ctr MAC: hmac-sha1 compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:+zkrXNJENs5EobFwHa8wpMDe6zPDfj975qLcPp4b4sg
debug1: Host '192.168.1.202' is known and matches the ECDSA host key.
debug1: Found key in /Users/Matt/.ssh/known_hosts:1
debug1: rekey after 4294967296 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: rekey after 4294967296 blocks
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /Users/Matt/.ssh/id_rsa
debug1: Server accepts key: pkalg rsa-sha2-512 blen 279
debug1: Authentication succeeded (publickey).
Authenticated to 192.168.1.202 ([192.168.1.202]:22).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: pledge: network
debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
debug1: Sending command: rsync --server -logDtpre.iLsfxC . /media/matt/MattsBackups/MacAir/
debug1: channel 0: free: client-session, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
Connection to 192.168.1.202 closed by remote host.
Transferred: sent 145304, received 13032 bytes, in 0.1 seconds
Bytes per second: sent 1373019.8, received 123143.2
debug1: Exit status -1
rsync: [sender] write error: Broken pipe (32)
rsync error: error in socket IO (code 10) at io.c(820) [sender=3.1.2]
Best Answer
Well as a last resort, I found an old 10/100 ethernet card from a windows 98 PC, and installed it in the server. After configuring it, I have had no more errors, over about 30 GB of data. I guess the built-in ethernet chipset didn't work well with ubuntu. Or I had somehow configured it incorrectly.
Edit: While I never found the root cause of my problem, be sure to check out the comment thread under @sourcejedi's answer. Big thanks to @sourcejedi, @sneep and @dentarg.