In university I normally SSH into the computer sciences server. However today I keep getting the following error: ssh_exchange_identification: Connection closed by remote host. SSHing with -v flags gives me the following.

OpenSSH_5.9p1, OpenSSL 0.9.8r 8 Feb 2011
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to ... [...] port 22.
debug1: Connection established.
debug3: Incorrect RSA1 identifier
debug3: Could not load "~/.ssh/id_rsa" as a RSA1 public key
debug1: identity file ~/.ssh/id_rsa type 1
debug1: identity file ~/.ssh/id_rsa-cert type -1
debug1: identity file ~/.ssh/id_dsa type -1
debug1: identity file ~/.ssh/id_dsa-cert type -1
ssh_exchange_identification: Connection closed by remote host

I've tried editing the hosts files but that won't help. Any suggestions?


This can happen when you have too many different keys to offer. You can easily fix this by adding IdentityFile ~/.ssh/id_rsa_keyname to your ~/.ssh/config entry used for this connection and a global IdentitiesOnly yes. This can look like this:


Host foo
    hostname server.example.com
    User myUserName
    IdentityFile ~/.ssh/id_rsa_keyname

Host *
    IdentitiesOnly yes

I ran into this same exact issue. My system log reflected:

/var/empty must be owned by root and not group or world-writable

Going to Disk Utility > Macintosh HD > Repair Disk Permissions reset the permissions of /var/empty and solved the problem for me.

  • 1
    I ran into this issue when upgrading from El Capitan to Sierra. After changing the owner of /var/empty to root (sudo chown root /var/empty/), ssh works like a charm again. Thx! – d4Rk Oct 25 '16 at 10:55

Little snitch was the problem for me. Rules > Incoming connections

You must do this from the Little Snitch application's preferences.

little snitch allow incoming ssh

  • 1
    This description is not helpful. Where in MacOS (what edition of MacOS?) do I go to Rules > Incoming connections ? – macetw Apr 28 '17 at 14:09

This error can occur due to multiple reasons, in my case it was after upgrading to High Sierra (macOS).

Host *
  UseKeychain yes
  AddKeysToAgent yes
  IdentityFile ~/.ssh/id_rsa


ssh -vvv  git@github.com

Further reading: https://github.com/jirsbek/SSH-keys-in-macOS-Sierra-keychain

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