DNS is not configured, I’m using /etc/hosts my entries are correct as far as I know, example: 192.168.122.1 kdc kdc.example.com #SyslogFacility AUTH
debug2: kex_parse_kexinit: first_kex_follows 0
A couple of things seem to be outdated: 1) sshd_config doesn’t accept GSSAPIDelegateCredentials but everything is working fine without it One CentOS 7 server.
At this time, it is not clear if all tasks related to Kerberos can be done through separate Kerberos, NFS, LDAP servers or through a unique FreeIPA server. Well, the KDC was also the NTP server and I had successful syncs from the client (chronyc sources). You can also watch Andrew Mallett‘s video about setting up a KDC (23min/2015). or can be done using ipaserver instead, my concern is when using ipaserver I will not get the same experience in the exam. How do i do that? debug1: Enabling compatibility mode for protocol 2.0 Create the Kerberos database (replace EXAMPLE.COM with you own realm): Note: It can be necessary to type keys on the keyboard to increase the entropy needed for the random data generation! You can follow the tutorial How To Use SSH Keys with DigitalOcean Droplets to set up SSH keys on each host if you haven’t already. 2) now firewalld has a service for kadmin, so can use that, I was able to get this to work on CentOS 7.2 using GSSAPIEnablek5users yes I try to maintain 7.0.1406 (CentOS) as I believe is used on the test. Both client (here kbclient.example.com) and KDC server (here kbserver.example.com) must be inside the same realm (usually your domain name written in upper case, here EXAMPLE.COM). Concerning the installation and configuration of a KDC Kerberos server, this is not part of the exam: it’s only for testing purpose. debug2: set_newkeys: mode 0 debug1: Server host key: ECDSA 88:d3:f7:85:f5:ba:40:98:8b:23:20:2f:51:8c:25:95 also enable debugging in sshd -d -d -d (/usr/lib/systemd/system/sshd.service)
We need to set up this file first before we can begin to communicate with our other computers.
As long as the ticket is valid, the client can access some services and doesn’t need to authenticate any more. I thought ssh_config was the client configuration file, and sshd_config was the server configuration file, not sure why we would need to restart the server daemon after making a “client” change. This is one way that Ansible simplifies the administration of servers. debug1: Next authentication method: password When troubleshooting Kerberos behaviour as root, you can assign a filename to the KRB5_TRACE environment variable.
Please explain. the process will hang. in /etc/hosts 192.168.1.11 kbserver.example.com kbserver As there are almost no report of the exam using RHEL 7.2 and none with RHEL 7.3, do you think it’s a good idea to test the configurations with so recent versions? debug3: load_hostkeys: found key type ECDSA in file /home/user01/.ssh/known_hosts:1 debug1: sending SSH2_MSG_KEX_ECDH_INIT Pre-requisites. Kerberos is an authentication protocol that was developed at MIT in 1988. Note: To delete a ticket, use the kdestroy command. debug3: load_hostkeys: loaded 1 keys It is good to have that knowledge, but it is difficult to set up. Before starting we need to install some packages on our centos machine. # default value. Execute the Kerberos administration tool: Add the KDC hostname to the Kerberos database: Create a local copy stored by default in the /etc/krb5.keytab file: Edit the /etc/ssh/sshd_config file and add/uncomment the following lines: Configure the PAM component at the command line: To get the correct firewall configuration (port udp/tcp 88 for Kerberos itself, port tcp 749 for kadmin communication), create the /etc/firewalld/services/kerberos.xml file and paste the following lines: Note: A Kerberos Firewalld configuration file already exists in the /usr/lib/firewalld/services directory but it doesn’t specify the kadmin protocol (749/tcp). The chapter 11 of the RHEL 7 System-Level Authentication Guide deals with the KDC configuration. Jul 02 16:22:29 kbserver sshd[7677]: Accepted gssapi-with-mic for user01 from 192.168.1.11 port 46943 ssh2, Can i setup Kerbose, NFS and Domain server in one VM ‘Server’ as a whole? But SSH/GSSAPI just doesn’t seem to be querying the correct principle. DigitalOcean makes it simple to launch in the cloud and scale up as you grow – whether you’re running one virtual machine or ten thousand. Setup kerberos client yum -y install krb5-workstation Transfer your /etc/krb5.conf (which got created from above command) from the KDC server to the client. The hosts file is fairly flexible and can be configured in a few different ways. Is there any reason i am getting this trying to add the root/admin princ? debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-sha1,[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 To begin exploring Ansible as a means of managing our various servers, we need to install the Ansible software on at least one machine. debug2: key: /home/user01/.ssh/id_dsa ((nil)), on server side: # journalctl -xeu sshd, if all is well in the log: If DNS is not configured, add the following lines in the /etc/hosts file (replace the specified ip addresses with yours): Caution: When adding a new line in the /etc/hosts file, you have to write the fully qualified domain name just after the ip address. Last login: Wed Jun 14 23:29:25 2017 You are almost asking for a FreeIPA server -> http://www.certdepot.net/rhel7-configure-freeipa-server/. Ansible works by configuring client machines from an computer with Ansible components installed and configured. debug3: authmethod_lookup gssapi-with-mic I’m on 7.3 and the issue is when you add “GSSAPIDelegateCredentials yes” to /etc/ssh/sshd_config, the sshd service fails to load due to “config error.” I have enabled only on the /etc/ssh/ssh_config” and sshd load properly.
Quick funny note.
debug2: key: /home/user01/.ssh/id_ecdsa ((nil)), debug1: expecting SSH2_MSG_NEWKEYS RHEL7: Use SELinux port labelling to allow services to use non-standard ports.
We'd like to help. debug1: identity file /home/user01/.ssh/id_ecdsa-cert type -1
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password $ KRB5_TRACE=/dev/stdout ssh -vvv kbserver.example.com debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-sha1,[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96 The Operating System on the exam may be different from the version you are studying on. debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,[email protected],[email protected],[email protected],aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
Configuration files are mainly written in the YAML data serialization format due to its expressive nature and its similarity to popular markup languages. I wrote a tutorial about this kind of problem (here). # This sshd was compiled with PATH=/usr/local/bin:/usr/bin. according to Sander van Vugt it is not, then this tutorial is mainly for kerberos client testing purpose and I don’t need to memorize it for the exam purpose? Jun 14 23:00:11 ipa.example.com systemd[1]: Failed to start OpenSSH server daemon. It’s a question to ask Red Hat representatives. Keep these examples in the file to help you learn Ansible’s configuration if you want to implement more complex scenarios in the future.
#HostKey /etc/ssh/ssh_host_key
debug2: we sent a password packet, wait for reply. Contribute to Open Source. Working on improving health and education, reducing inequality, and spurring economic growth? RHEL7: Use /proc/sys and sysctl to modify and set kernel runtime parameters. To get Ansible for CentOS 7, first ensure that the CentOS 7 EPEL repository is installed: Once the repository is installed, install Ansible with yum: We now have all of the software required to administer our servers through Ansible.
Hop onto the client server, install the Kerberos client package and add some host principals: To configure this, you would add this block to your hosts file: Hosts can be in multiple groups and groups can configure parameters for all of their members. I’m going to change the tutorial according to your remark. # sshd_config(5) for more information. Can we install both Client and Server in same machine? debug3: authmethod_is_enabled gssapi-with-mic Modules can be written in any language and communicate in standard JSON. and feed entropy via command: debug3: authmethod_is_enabled password How to test out the user login when using NFS to authenticate by kerboros in that VM server. The tutorials have been tested on CentOS 7.0, 7.1 and 7.2 but I’m not sure about 7.3, which could explain your problems. # possible, but leave them commented. You can learn more in Configuration Management 101: Writing Ansible Playbooks and How To Create Ansible Playbooks to Automate System Configuration on Ubuntu. The result was that SSHD then failed to run, taking down a number of services with it (I spotted this when nmap marked port 22 as closed, along with several others that had been working fine).