for a while I have been having issues with ssh on my macbook (Big Sur). I first noticed with git. Now I am trying to connect to a VM and after I enter my password the terminal freezes for a while and then I get:client_loop: send disconnect: Broken pipe.
I have tried adding ServerAliveInterval, IPQoS and other solutions I found, but nothing seems to work.
Host * SendEnv LANG LC_* ServerAliveInterval 120 IPQoS lowdelay throughput ServerAliveCountMax 5This is the verbose output:
ssh -vvv mmm@server
OpenSSH_8.1p1, LibreSSL 2.7.3
debug1: Reading configuration data /Users/mmm/.ssh/config
debug1: /Users/mmm/.ssh/config line 1: Applying options for *
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 47: Applying options for *
debug1: Connecting to server port 22.
debug1: Connection established.
debug1: identity file /Users/mmm/.ssh/id_rsa type 0
debug1: identity file /Users/mmm/.ssh/id_rsa-cert type -1
debug1: identity file /Users/mmm/.ssh/id_dsa type -1
debug1: identity file /Users/mmm/.ssh/id_dsa-cert type -1
debug1: identity file /Users/mmm/.ssh/id_ecdsa type -1
debug1: identity file /Users/mmm/.ssh/id_ecdsa-cert type -1
debug1: identity file /Users/mmm/.ssh/id_ed25519 type -1
debug1: identity file /Users/mmm/.ssh/id_ed25519-cert type -1
debug1: identity file /Users/mmm/.ssh/id_xmss type -1
debug1: identity file /Users/mmm/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_8.1
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.9p1 Debian-10+deb10u2
debug1: match: OpenSSH_7.9p1 Debian-10+deb10u2 pat OpenSSH* compat 0x04000000
debug3: fd 5 is O_NONBLOCK
debug1: Authenticating to server:22 as 'mmm'
debug3: hostkeys_foreach: reading file "/Users/mmm/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/mmm/.ssh/known_hosts:6
debug3: load_hostkeys: loaded 1 keys from server
debug3: order_hostkeyalgs: prefer hostkeyalgs: ,,,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: ,,,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,,,,,ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: ,aes128-ctr,aes192-ctr,aes256-ctr,,
debug2: ciphers stoc: ,aes128-ctr,aes192-ctr,aes256-ctr,,
debug2: MACs ctos: ,,,,,,,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: ,,,,,,,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,,zlib
debug2: compression stoc: none,,zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1
debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ssh-rsa,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: ,aes128-ctr,aes192-ctr,aes256-ctr,,
debug2: ciphers stoc: ,aes128-ctr,aes192-ctr,aes256-ctr,,
debug2: MACs ctos: ,,,,,,,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: ,,,,,,,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,
debug2: compression stoc: none,
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: MAC: <implicit> compression: none
debug1: kex: client->server cipher: MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:Gy6pf90yIod/x4QkXV3gIa1u0W8DuNRnsLHNe+JWzU
debug3: hostkeys_foreach: reading file "/Users/mmm/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/mmm/.ssh/known_hosts:6
debug3: load_hostkeys: loaded 1 keys from server
debug3: hostkeys_foreach: reading file "/Users/mmm/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /Users/mmm/.ssh/known_hosts:6
debug3: load_hostkeys: loaded 1 keys from IP
debug1: Host 'server' is known and matches the ECDSA host key.
debug1: Found key in /Users/mmm/.ssh/known_hosts:6
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey out after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey in after 134217728 blocks
debug1: Will attempt key: /Users/mmm/.ssh/id_rsa RSA SHA256:Bonpo3/yi3FnTjV2Md5en+iJzXYNcHsCwpnJyaVDLI
debug1: Will attempt key: /Users/mmm/.ssh/id_dsa
debug1: Will attempt key: /Users/mmm/.ssh/id_ecdsa
debug1: Will attempt key: /Users/mmm/.ssh/id_ed25519
debug1: Will attempt key: /Users/mmm/.ssh/id_xmss
debug2: pubkey_prepare: done
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<ssh-ed25519,ssh-rsa,rsa-sha2-256,rsa-sha2-512,ssh-dss,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey
debug3: start over, passed a different list publickey
debug3: preferred publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering public key: /Users/mmm/.ssh/id_rsa RSA SHA256:Bonpo3/yi3FnTjV2Md5en+iJzXYNcHsCwpnJyaVDLI
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 60
debug1: Server accepts key: /Users/mmm/.ssh/id_rsa RSA SHA256:Bonpo3/yi3FnTjV2Md5en+iJzXYNcHsCwpnJyaVDLI
debug3: sign_and_send_pubkey: RSA SHA256:Bonpo3/yi3FnTjV2Md5en+iJzXYNcHsCwpnJyaVDLI
debug3: sign_and_send_pubkey: signing using rsa-sha2-512
Enter passphrase for key '/Users/mmm/.ssh/id_rsa':
debug3: send packet: type 50
debug3: receive packet: type 52
debug1: Authentication succeeded (publickey).
Authenticated to server ([IP]:22).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug3: send packet: type 90
debug1: Requesting
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: network
debug3: receive packet: type 80
debug1: client_input_global_request: rtype want_reply 0
debug3: receive packet: type 4
debug1: Remote: /home/mmm/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
debug3: receive packet: type 4
debug1: Remote: /home/mmm/.ssh/authorized_keys:1: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
debug3: receive packet: type 91
debug2: channel_input_open_confirmation: channel 0: callback start
debug2: fd 5 setting TCP_NODELAY
debug3: ssh_packet_set_tos: set IP_TOS 0x08
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 1
debug3: send packet: type 98
debug1: Sending environment.
debug3: Ignored env TERM_PROGRAM
debug3: Ignored env TERM
debug3: Ignored env SHELL
debug3: Ignored env TMPDIR
debug3: Ignored env TERM_PROGRAM_VERSION
debug3: Ignored env TERM_SESSION_ID
debug3: Ignored env USER
debug3: Ignored env COMMAND_MODE
debug3: Ignored env SSH_AUTH_SOCK
debug3: Ignored env __CF_USER_TEXT_ENCODING
debug3: Ignored env PATH
debug3: Ignored env __CFBundleIdentifier
debug3: Ignored env PWD
debug3: Ignored env ITERM_PROFILE
debug3: Ignored env XPC_FLAGS
debug3: Ignored env XPC_SERVICE_NAME
debug3: Ignored env SHLVL
debug3: Ignored env HOME
debug3: Ignored env COLORFGBG
debug1: Sending env LC_TERMINAL_VERSION = 3.4.4
debug2: channel 0: request env confirm 0
debug3: send packet: type 98
debug3: Ignored env ITERM_SESSION_ID
debug3: Ignored env LOGNAME
debug1: Sending env LC_CTYPE = UTF-8
debug2: channel 0: request env confirm 0
debug3: send packet: type 98
debug1: Sending env LC_TERMINAL = iTerm2
debug2: channel 0: request env confirm 0
debug3: send packet: type 98
debug3: Ignored env COLORTERM
debug3: Ignored env _
debug2: channel 0: request shell confirm 1
debug3: send packet: type 98
debug2: channel_input_open_confirmation: channel 0: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug3: send packet: type 80
debug3: send packet: type 1
client_loop: send disconnect: Broken pipe1 Answer
I had the same problem on my MAC OS Catalina 10.15.5 After some research on google I added the following line to my /etc/ssh/ssh_config Host * IPQoS=throughput And it fixed the problem. Note that I initially tried to add the same in .ssh/config file (i had to create it) and apparently it is not working on MAC. Unlike any Linux distro. So use /etc/ssh/ssh_config on MAC to configure your SSH Client
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