Mailing List Archive

ssh -g -L => bind: Address already in use, but it works anyway
Hi,

I'm trying to use ssh for port forwarding.
So far ssh -L has worked just fine for that purpose.
Now I want to bind the port to all interfaces,
so I tried ssh -g -L. The SSH session seems to launch
successfully, and the port is forwarded as expected,
and it is bound to all interfaces. However,
I get an error message as the remote session is
launched: "bind: Address already in use".

I also tried ssh -b but ssh still complains "Address already in use".

I have verified that that there actually isn't any
other process using the port I want.
I can't find any additional info in /var/log/messages
or elsewhere in /var/log/.

Since the port forwarding seems to work, I'm not
too worried about it, but I'd like to understand what's
going on. Any ideas?

ssh on the client reports its version as
"OpenSSH_3.9p1, OpenSSL 0.9.7a Feb 19 2003"
and sshd on the server is openssh-server-4.5p1-6.fc7
as reported by rpm.

Thanks for your help,

Robert Dodier

PS. Here is a debug log.
There is more to to it, but I cut it off at "Address already in use".

$ ssh -vvv -g -L 1069:*:1069 192.168.0.25
OpenSSH_3.9p1, OpenSSL 0.9.7a Feb 19 2003
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 192.168.0.25 [192.168.0.25] port 22.
debug1: Connection established.
debug1: identity file /home/robertdodier/.ssh/identity type -1
debug3: Not a RSA1 key file /home/robertdodier/.ssh/id_rsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file /home/robertdodier/.ssh/id_rsa type -1
debug1: identity file /home/robertdodier/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.5
debug1: match: OpenSSH_4.5 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_3.9p1
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit:
diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit:
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit:
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit:
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib
debug2: kex_parse_kexinit: none,zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit:
diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit:
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit:
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit:
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib@openssh.com
debug2: kex_parse_kexinit: none,zlib@openssh.com
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_init: found hmac-md5
debug1: kex: server->client aes128-cbc hmac-md5 none
debug2: mac_init: found hmac-md5
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 142/256
debug2: bits set: 488/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: check_host_in_hostfile: filename /home/robertdodier/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 58
debug1: Host '192.168.0.25' is known and matches the RSA host key.
debug1: Found key in /home/robertdodier/.ssh/known_hosts:58
debug2: bits set: 520/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /home/robertdodier/.ssh/identity ((nil))
debug2: key: /home/robertdodier/.ssh/id_rsa ((nil))
debug2: key: /home/robertdodier/.ssh/id_dsa ((nil))
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug3: start over, passed a different list publickey,gssapi-with-mic,password
debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup gssapi-with-mic
debug3: remaining preferred: publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-with-mic
debug1: Next authentication method: gssapi-with-mic
debug1: An invalid name was supplied
Cannot determine realm for numeric host address

debug1: An invalid name was supplied
Cannot determine realm for numeric host address

debug2: we did not send a packet, disable method
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/robertdodier/.ssh/identity
debug3: no such identity: /home/robertdodier/.ssh/identity
debug1: Trying private key: /home/robertdodier/.ssh/id_rsa
debug1: read PEM private key done: type RSA
debug3: sign_and_send_pubkey
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,gssapi-with-mic,password
debug1: Trying private key: /home/robertdodier/.ssh/id_dsa
debug3: no such identity: /home/robertdodier/.ssh/id_dsa
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
robertdodier@192.168.0.25's password:
debug3: packet_send2: adding 48 (len 72 padlen 8 extra_pad 64)
debug2: we sent a password packet, wait for reply
debug1: Authentication succeeded (password).
debug1: Connections to local port 1069 forwarded to remote address *:1069
debug1: Local forwarding listening on :: port 1069.
debug2: fd 4 setting O_NONBLOCK
debug3: fd 4 is O_NONBLOCK
debug1: channel 0: new [port listener]
debug1: Local forwarding listening on 0.0.0.0 port 1069.
bind: Address already in use
Re: ssh -g -L => bind: Address already in use, but it works anyway [ In reply to ]
Hi, for the record, I was told to try -4 on the command line.
Indeed, that quiets the "Address already in use" message.
Maybe this is useful to someone else.

best,

Robert Dodier


On Fri, Jan 28, 2011 at 9:38 AM, Robert Dodier <robert@infotility.com> wrote:
> Hi,
>
> I'm trying to use ssh for port forwarding.
> So far ssh -L has worked just fine for that purpose.
> Now I want to bind the port to all interfaces,
> so I tried ssh -g -L. The SSH session seems to launch
> successfully, and the port is forwarded as expected,
> and it is bound to all interfaces. However,
> I get an error message as the remote session is
> launched: "bind: Address already in use".
>
> I also tried ssh -b but ssh still complains "Address already in use".
>
> I have verified that that there actually isn't any
> other process using the port I want.
> I can't find any additional info in /var/log/messages
> or elsewhere in /var/log/.
>
> Since the port forwarding seems to work, I'm not
> too worried about it, but I'd like to understand what's
> going on. Any ideas?
>
> ssh on the client reports its version as
> "OpenSSH_3.9p1, OpenSSL 0.9.7a Feb 19 2003"
> and sshd on the server is openssh-server-4.5p1-6.fc7
> as reported by rpm.
>
> Thanks for your help,
>
> Robert Dodier