Depending how many you are poking, you might consider these adjustments too:-
The blue -q is to suppress some of the normal output to keep your log file a little clearer, however the log file will probably still collect anything that is displaed by the server login process e.g. from /etc/profile or ~/.bashrc
I've added the green to speed up the timeout if the server does not respond. You might want to adjust it depending on what your network will allow.
The red hostname is a command to run on the server you are connecting to. You have $HOSTNAME which may be undefined or set to anything in the shell's environment prior to this script.
What output do you actually want? Is it a list of hosts you could not connect to? If you can open the IP connection, but if fails to sign in how would you handle that? You script would probably just hang. Other conditions may cause your script to carry on to the next host immediately, e.g. the server's public key is different and you get an alert about a possible man-in-the-middle attack. The ssh exits with a non-zero return code, but you don't check. Perhaps you just want a list of successes to then target those that don't let you connect. Knowing the goal would be useful for us.
Hi. I have a kornshell script that runs on a daily basis as a cron job. Part of what the script does is copy the folder contents from another server to the current server (server where KSH script is running).
I have a scp command, as follows:
scp $REMOTE_HOST:$REMOTE_FILE_DIR/* $TMP_DIR
... (8 Replies)
Hi,
I am new to Shell Scripting. Can anybody help me in writing a Script Which Could Login from a Unix box to a Remote Unix box which accepts the user credentials automatically and display the result for checking the Disk Space Utilisation (Without running any SSH agent). (1 Reply)
Hi all,
I'm writing a script that chooses the best computer available in an open lab. The script works great except every now and then there is a dead computer in the lab that begins the ssh handshaking, but freezes after the following:
debug1: Offering public key:
When the script happens... (2 Replies)
Hello there.
I'm fairly new to Linux, but I am connecting via SSH and PuTTY to a remote server, and I am running a fairly heavy MySQL script in a PHP page.
Our connection here is dodgy to say the least and I get continuous disconnections.
My question is, when I get disconnected, does my... (4 Replies)
Hi all,
Im new at scripting and i need to run a few commands at work every hours so i decide to make a script but on 1 of the steps i have a the follwoing problem:
The command i do is this:
#!/bin/bash
ssh root@asdasd001 'mysql -h A-db-1 -uroot -password --execute "show slave status"'... (3 Replies)
Hello;
I regularly run monitoring scripts over ssh to monitoring scripts
But whenever a server is hung or in maintenance mode, my script hangs..
Are there anyways to trap exit status and be on my way ??
Looked at the ssh manpage and all I can see is a "-q" option for quiet mode ..
Thank... (2 Replies)
Hey,
I need a script that tries to connect via SSH to a remote server
and that remote server might not be up yet, so retry until succeed
the error message I get if the server is not up yet is:
ssh: connect to host 127.0.0.1 port 40001: Connection refused
any idea of a good way to do it ?
... (5 Replies)
Dear Folks,
I am trying to read a config file contains ip and port numbers.
i want to read each line of the config file and check ssh connection is happening or not.
Kindly guide.
Config file:
abc@1.2.342 22
abc@1.2.343 22
abc@1.2.344 22
abc@1.2.345 22... (9 Replies)
Hello guys!
I am setting up a script to access a unix remote server. My problem is that when I put the ssh line "my host", the script does not wait for the server response asking for the password to execute the line in which I put the password, that is, I need to put a form in which script has a... (1 Reply)
Discussion started by: aroucasp
1 Replies
LEARN ABOUT SUNOS
ssh-keyscan
ssh-keyscan(1) User Commands ssh-keyscan(1)NAME
ssh-keyscan - gather public ssh host keys of a number of hosts
SYNOPSIS
ssh-keyscan [-v46] [-p port] [-T timeout] [-t type] [-f file] [-] [host... | addrlist namelist] [...]
DESCRIPTION
ssh-keyscan is a utility for gathering the public ssh host keys of a number of hosts. It was designed to aid in building and verifying
ssh_known_hosts files. ssh-keyscan provides a minimal interface suitable for use by shell and perl scripts. The output of ssh-keyscan is
directed to standard output.
ssh-keyscan uses non-blocking socket I/O to contact as many hosts as possible in parallel, so it is very efficient. The keys from a domain
of 1,000 hosts can be collected in tens of seconds, even when some of those hosts are down or do not run ssh. For scanning, one does not
need login access to the machines that are being scanned, nor does the scanning process involve any encryption.
File Format
Input format:
1.2.3.4,1.2.4.4
name.my.domain,name,n.my.domain,n,1.2.3.4,1.2.4.4
Output format for rsa1 keys:
host-or-namelist bits exponent modulus
Output format for rsa and dsa keys, where keytype is either ssh-rsa or `ssh-dsa:
host-or-namelist keytype base64-encoded-key
OPTIONS
The following options are supported:
-f filename Read hosts or addrlist namelist pairs from this file, one per line. If you specity - instead of a filename, ssh-
keyscan reads hosts or addrlist namelist pairs from the standard input.
-p port Port to connect to on the remote host.
-T timeout Set the timeout for connection attempts. If timeout seconds have elapsed since a connection was initiated to a host
or since the last time anything was read from that host, the connection is closed and the host in question is con-
sidered unavailable. The default is for timeout is 5 seconds.
-t type Specify the type of the key to fetch from the scanned hosts. The possible values for type are rsa1 for protocol
version 1 and rsa or dsa for protocol version 2. Specify multiple values by separating them with commas. The
default is rsa1.
-v Specify verbose mode. Print debugging messages about progress.
-4 Force to use IPv4 addresses only.
-6 Forces to use IPv6 addresses only.
SECURITY
If a ssh_known_hosts file is constructed using ssh-keyscan without verifying the keys, users are vulnerable to man-in-the-middle attacks.
If the security model allows such a risk, ssh-keyscan can help in the detection of tampered keyfiles or man-in-the-middle attacks which
have begun after the ssh_known_hosts file was created.
EXAMPLES
Example 1: Printing the rsa1 Host Key
The following example prints the rsa1 host key for machine hostname:
$ ssh-keyscan hostname
Example 2: Finding All Hosts
The following commands finds all hosts from the file ssh_hosts which have new or different keys from those in the sorted file
ssh_known_hosts:
$ ssh-keyscan -t rsa,dsa -f ssh_hosts |
sort -u - ssh_known_hosts | diff ssh_known_hosts -
FILES
/etc/ssh_known_hosts
EXIT STATUS
The following exit values are returned:
0 No usage errors. ssh-keyscan might or might not have succeeded or failed to scan one, more or all of the given hosts.
1 Usage error.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWsshu |
+-----------------------------+-----------------------------+
|Interface Stability |Evolving |
+-----------------------------+-----------------------------+
SEE ALSO ssh(1), sshd(1M), attributes(5)AUTHORS
David Mazieres wrote the initial version, and Wayne Davison added suppport for protocol version 2.
BUGS
ssh--keyscan generates
Connection closed by remote host
messages on the consoles of all machines it scans if the server is older than version 2.9. This is because ssh-keyscan opens a connection
to the ssh port, reads the public key, and drops the connection as soon as it gets the key.
SunOS 5.10 24 Jul 2004 ssh-keyscan(1)