the secure shell (SSH) daemon

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2answers
21 views

Is there a way to tell how a user authenticated their SSH connection ? i.e. whether it was by password or by public key?

I'm locking down my server to use public-key only. I just want to make sure before I flip the switch that all my users have already made the transition, and nobody is left using passwords to log in.
2
votes
1answer
20 views

Display full settings of sshd

The OpenSSH daemon has many "default" values for its settings. So looking at the sshd_config might not give someone the complete set of active settings. How to display the full sshd configuration ...
7
votes
1answer
125 views

Blocking SSH Brute Force attacks on IPv6

I recently had to work with some servers that have an IPv6 connection and I was surprised to find out that fail2ban does not have IPv6 support, neither does denyhosts. Searching on google I found that ...
0
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1answer
35 views

Configure ssh users under a group [closed]

I created a group called ssh_group and currently have nearly 20 users under AllowUsers in /etc/ssh/sshd_config. After I created the ssh_group, I modified the AllowGroups line like this AllowGroups ...
0
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1answer
28 views

Adding user override to sshd_config causes ssh_exchange_identification error

I wanted to allow SSH TCP forwarding for a specific user, so I added this section to sshd_config: Match User rainmannoodles AllowTcpForwarding yes TCPKeepAlive yes After that change, I get ...
0
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0answers
29 views

SMTP traffic being forwarded through SSH even do AllowTcpForwarding is disabled

I have a situation on one server, where it seems to be spaming over traffic being sent over SSH tunnel. Output below shows connections being made to remote SMTP server that seem to be initiated over ...
2
votes
1answer
21 views

Use two SSH ports, but open only one?

My iptables.conf looks loosely like this: -A INPUT -p tcp --dport 65000 -j ACCEPT -A INPUT -j DROP My sshd_config looks like this: Port 22 Port 65000 #AddressFamily any #ListenAddress 0.0.0.0 ...
2
votes
0answers
36 views

Two ISP and redirecting traffic

I have a gateway with two ISP connected to eth0 and eth2. There is also a eth1 with local network. I'm trying to group some services in one interface and some in the second: incoming traffic 1 ...
3
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3answers
101 views

How to start SSH daemon on boot on Linux Mint Debian v2

I'm using Linux Mint Debian v2, 64-bit. I noticed recently that my ssh daemon does not start automatically on boot. It used to. I'm not sure if it had to do with my UFW configuration or sshd_config ...
0
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0answers
71 views

xterm Xt error: Can't open display: localhost:11.0

I'm on a windows machine running Xming32, putty and plink. I have two centos boxes. One I can connect to just fine. The other I can't. I'm trying with this command plink -C -v jdearing@BROKENHOST ...
3
votes
1answer
33 views

sudo command inside heredoc block in a ssh session is not working

When i use heredoc and put all the commands inside heredoc as, ssh -t -i master.pem cloud-user@$1 <<EOSSH sudo service x restart sudo service y restart EOSSH it throws error as, ...
1
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1answer
66 views

How to ensure ssh via cgroups on centos?

When some cpu-intensive processes are running on the server, chances are that we could not log in to this machine with error 'operation timeout' via ssh command. According to this post answered by ...
1
vote
1answer
176 views

CentOS 7 - ssh login is refused when i use ssh public key, but only works with username password

I am not able to login via SSH key. I place my id_rsa.pub key in the /root/.ssh/authorized_keys [root@s .ssh]# ll total 4 -rw------- 1 root root 403 Jun 8 00:44 authorized_keys [root@s ~]# cat ...
2
votes
1answer
41 views

Is sshd_config TPCKeepAlive still using unencrypted channel and therefore vulnerable

This post from 2008 in ubuntuforums recommends disabling TCPKeepAlive Disable TCP KeepAlive messages. These messages are spoofable and are sent outside of the encrypted channel, and ...
4
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1answer
82 views

Uselogin in sshd_config

I was looking through my sshd_config file and I found this: #Uselogin no I know it's commented but there is no explanation above it and when I google it, I get this: Don't use the traditional ...
4
votes
5answers
111 views

Multiline Text Processing : Editing sshd_config

I have multiple blocks at the end of my sshd_config files like theses: Match User FOO ChrootDirectory /srv/www/FOO AllowTCPForwarding no X11Forwarding no ForceCommand internal-sftp ...
0
votes
1answer
54 views

Unable to login with SSH-RSA key

This post is following this question : Authentication refused: bad ownership or modes for file /var/git/.ssh/authorized_keys . The issue as exposed there is solved (about files modes of the ...
2
votes
3answers
514 views

Authentication refused: bad ownership or modes for file /var/git/.ssh/authorized_keys [duplicate]

EDIT The issue as exposed here is solved (about files modes of the .ssh folder. But an other issue persists so I create a new question : > Unable to login with SSH-RSA key I can no longer ...
2
votes
0answers
66 views

How to tell systemd to start sshd later in the boot sequence?

My sshd_config file specifies it should listen on some specific IP addresses instead of on all IP addresses. The problem is that one of these NICs doesn't come up until later in the boot sequence. ...
2
votes
1answer
47 views

Configure OpenSSH server not to require password *or* key for a particular user

For the purpose of a training session, I'd like to make it possible for a particular user to connect without requiring a password or key-based authentication. I do not know the IPs or other data of ...
2
votes
2answers
95 views

Passwordless login only works using directly invoked sshd on server

I've been through as many of the bugfixes as I can find for the classic ssh key issue : I've set up my public and private keys "correctly" but passwordless login still doesn't work. The details : ...
0
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0answers
56 views

fedora 21 workstation and sshguard 1.5 set up

I installed fedora 21 workstation, and I compiled and implemented sshguard 1.5 since I could not find rpm 64. How do I best set up sshguard so that it protects the server? Esp. in terms of reading the ...
0
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1answer
123 views

SSH login too slow in Centos 6.6 [closed]

SSH login take too much time in my CentOS machine, and also a ftp server is running on it. Please help me to speedup the login time for both root and ftp user. I tried some tricks but no ...
1
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1answer
74 views

Can't connect to the sshd in my unprivileged LXC guest. What to do?

So you configured your unprivileged LXC guest, by defining lxc.id_map = u 0 1000000000 10000 lxc.id_map = g 0 1000000000 10000 and of course assigning those subordinate UID/GID ranges to an ...
1
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1answer
139 views

Is there a canonical method to restrict ssh access to certain IP addresses in Unix?

I checked man pages related to ssh on OS X and other systems and tried using hosts.allow and hosts.deny files as per this post, and sshd_config to no avail. $ cat /etc/hosts.allow sshd: ...
2
votes
1answer
37 views

SSH demon not installed in linux embedded device

I have an embedded device which runs linux(arm). I am trying to update the executable through ethernet using scp command. But I got to know that sshd is not running in the device . I need to install ...
0
votes
0answers
51 views

How do I configure SSHd to require 2 (or more) passwords to log in

I'm asking because I want to setup a server that cannot be administered by any single admin, not without the permission (and oversight) of one other authorized admin (there can be many). Since there ...
0
votes
1answer
51 views

how to view failed login attempts?

I tried to view failed user login attempts since a specific time. But all methods I found by searching the internet does not work. I am using openSUSE 13.2. journalctl -a --no-pager ...
2
votes
1answer
76 views

How to make sshd listen to two ports, but restrict one of them to a single source address?

I need sshd to listen both on port 22225 (allowing connections on that port from any IP) and port 22 (allowing just a single static IP on that port). In other words, listen on two ports at the same ...
0
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0answers
44 views

ssh agent-forwarding with lxc

I have a "little" problem I try to ssh using putty and pageant to server, than to ssh into lxc-container and than to other server. But no publickey is used, it prompts for password (at last hop). ...
2
votes
1answer
152 views

How to use ssh over http or https?

I have a linux fedora21 client laptop behind a corporate firewall (which lets through http and https ports but not ssh 22) and I have a linux fedora21 server at home behind my own router. Browsing ...
0
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1answer
23 views

Set MasSessions to SSH does not take effect

I got a server with enabled ssh. To prevent attacks and to fit to my needs, I just need one connection at the same time to my server. So, I tried to set MaxSessions paramater to 1 in ...
1
vote
2answers
121 views

remote shell - are there any non-ssh based alternatives?

Are there any alternative SSH servers other than SSHD? One that is not SSH based? Ideally one that can be installed from offical Debian repository, that listens on a port other than port 22. (To ...
0
votes
1answer
2k views

How to open the SSH port 22? [closed]

I have installed the ssh utility on an embedded system but I can't connect to it. I am able to ssh from the device to another computer on the network but not the other way around. The only port ...
4
votes
1answer
399 views

Why did sshd delete my /dev/zero?

When I do lsof +c 0 | grep /dev/zero, I see the following two lines: sshd 19064 root DEL REG 0,4 497862 /dev/zero sshd 19064 root DEL REG 0,4 498725 /dev/zero ...
1
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1answer
121 views

Restrict SSH login to local network: VPN connection not allowed

There are two (unix) users who are allowed to connect to my Debian Wheezy server using ssh: git and peter. While git is allowed to connect from everywhere, peter (who is in the sudo group) should be ...
1
vote
1answer
131 views

SSH message, source of a after-login greeting command

On a server previously adminstered by someone else i noticed non-standard after-login ssh message. It looks like this: In case of problems please send an email to ....@..... Disk quotas for user ...
0
votes
2answers
208 views

SSH banner not showing

I have a fresh installation of OpenSSH. In the /etc/ssh/sshd_config I have the following entry: Banner /etc/issue.net I have restarted the SSH deamon using: sudo /etc/init.d/ssh restart. Now, ...
1
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2answers
203 views

SSH via cert-authority

I'm trying to use SSH using signed certificates. I'm using ssh -i keys/client.key to connect to the target device. If I generate a public key from that private key (with ssh-keygen -y -f ...
-2
votes
2answers
236 views

ssh gives an illegal user error

Setup a new server and was able to ssh in successfully until I updated apache and php, which maybe upgraded sshd? # grep -i allow /etc/ssh/sshd_config | grep -v "^\($\|#\)" AllowUser lbutlr ...
4
votes
2answers
162 views

which config file is openssh sshd using?

Where can i check/verify which config file sshd is using? I know you can change the config file to use by using -f command, but is there a way to echo which config file is currently being used or is ...
0
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0answers
11 views

SSH tunneling error: “channel 1016:: open failed: administratively prohibited: open failed” [duplicate]

when I use config file in the /home/username/.ssh/config to connect to localhost with ssh, I get the following results: channel 1016: open failed: administratively prohibited: open failed channel ...
1
vote
1answer
4k views

Forwarding X11 not working - Error: Can't open display: localhost:11.0

LM 17 Xfce OpenSSH_6.6.1p1 Ubuntu-2ubuntu2 Despite googling everywhere, I cannot seem to get this to work. I keep getting this error. $ xlogo Error: Can't open display: localhost:10.0 I have tried ...
2
votes
2answers
720 views

RHEL 7 (CentOS 7) security / ssh / sshd_config advise requested

I am not a sysadmin and try to create a more or less secure web server (LAMP based CentOS 7). I read several tutorials about setup an initial CentOS 7 droplet and got everything running fine. ...
0
votes
1answer
37 views

Migrate SSHD sftp Logging

currently my messages log file is filling up with Dec 19 08:46:43 XXXXXXXXX sftp-server[32357]: closedir and similar messages - is there a setting that I can move all sftp-server messages off to ...
0
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1answer
2k views

CentOS 7 add new user with root privileges

I am reading this tutorial, and trying to create a new user with root privileges and then block root access via ssh in a CentOS 7 server. The problem is that the new user is blocked from doing root ...
1
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0answers
139 views

SSHD_CONFIG keeps corrupting on reverse SSH setup

I have a reverse SSH setup to traverse an impenetrable CGN NAT. It works well, but the SSHD daemon on the client behind the NAT keeps dieing for unknown reasons (fails to start-up). The client ...
1
vote
1answer
91 views

Jail in chroot in debian 7.5 - Privileges Separation problem

I'm trying to create a jail for a user in my server. Let's call the user "juser". What do I want to achieve? I want an ssh user to be jailed in his home folder and not have any access (whatsoever) on ...
0
votes
1answer
74 views

Memory Required for SSH-only Linux Setup

I am attempting to set up a minimal Debian or CentOS installation for internal network access. The purpose of the setup will be to allow SSH access into the rest of the internal network—that's it. It ...
4
votes
1answer
11k views

installing fail2ban on CentOS 7

I am using @GarethTheRed 's answer to this question to install fail2ban on a remote CentOS 7 server. I am able to complete all the steps up until tail -f /var/log/fail2ban.log, at which point I get ...