Personal Data

(More info on request)
NameMark Janssen
LanguagesDutch (native)
English (fluent)
German (conversational)
E-mailmark (at) sig-io (dot) nl

Education and Training

2011Competa: AIX Essentials
2010Novell Certified Linux Administrator
2009Sun Certified Solaris Administrator (Solaris 10)
2009SNIA Certified Storage Professional, only attended training, haven't done the exam yet
2008ITIL Foundations
2007Linux Professional Institute, LPI-2 cerfitication (verify)
2005Linux Professional Institute, LPI-1 certification (verify)
2000 - 2001Brainbench Certifications: (Check them on the brainbench site, some have since expired (after 1 year))
  • 4.77: Master level at Unix Administration (general) (top 1%)
  • 4.31: Master level at Unix Administration (HP)
  • 4.49: Master level at Linux Administration (general) (top 5%)
  • 4.58: Master level at Apache 1.3 Administration
  • 3.93: Internet Concepts
  • 3.83: Internet Security
  • 3.88: TCP/IP Administration
  • 3.64: Written English
  • Brainbench Unix MVP (Most Valued Professional)
2004Megabit 2002, 2003 and 2004, Networking conference and tutorials, Ede, Netherlands (crew-member)
2003CCC Camp 2003, Berlin, Germany (visitor)
2002Sane Conference, Maastricht (visitor, tutorials)
2002Linux Kongress 2002, Cologne, Germany (visitor)
2001Linux Kongress 2001, Linux Conference and Lectures, Enschede, Netherlands (visitor)
2001HAL-2001, Hackers At Large, Security Conference and Lectures, Enschede, Netherlands (visitor)
2001LDAP, Short introduction into using LDAP, Hewlett-Packard, Netherlands
2000SANE-2000, System Administration and Networking Event, Maastricht, Netherlands (visitor)
1999 - 2004Bi-Yearly NLUUG Unix Conferences, Unix Conference and Lectures, Ede, Netherlands (visitor)
1999HP-UX 10.X System Administration, Hewlett-Packard, Netherlands
1997Crashcourse Windows NT, InfoSupport, Venendaal, Netherlands
1994-1998Computer Science, Haagse Hogeschool, The Hague, Netherlands
1989-1994Havo, Alfrink College, Zoetermeer, Netherlands


Operating Systems
  • Debian Linux version 3-6 (specialist)
  • Red Hat Enterprise Linux 4-6 (And derivatives CentOS, ScientificLinux and Oracle Unbreakable Linux) (specialist)
  • Ubuntu (all versions) (specialist)
  • Suse Linux Enterprise version 10-11 (experienced)
  • HP-UX 9.x - 11.x (experienced)
  • AIX 4.3 - 6 (experienced)
  • Solaris 7 - 11 (experienced)
  • Microsoft Windows NT/XP/2000/2003/2008 (basic knowledge)
  • Cisco IOS (basic knowledge)
  • Juniper JunOS J-Series (basic knowledge)
Programming Languages
  • C (basic knowledge)
  • Perl (experienced)
  • Php (basic knowledge)
  • Sql (basic knowledge)
  • Shell scripting (experienced)
  • Expect (basic knowledge)
  • Tcl/Tk (basic knowledge)
ApplicationsNetVault, Iplanet, Apache, Sendmail, Courier, Postfix, Legato Networker, Squid, MySQL, HP-Sam, and many others. Very broad knowledge and experience with most-used open source tools and applications.
NetworkingTCP/IP (v4/v6), Routing, Firewalling, Proxying, DNS, NFS, NIS, Samba/SMB, SMTP
SecurityOpenSSH, Firewalling, Snort Intrusion Detection, host auditing

Job Experience

Some of the jobs described were done under the flag of the Consulting companies 'Unix Support Netherlands' (USN), 'SyConOS IT', 'Cohesion', and 'Snow'. Starting 2011, all my contracting work will be done under the flag of Sig-I/O automatisering. Please see the Sig-I/O website for information.

PeriodCompanyJob Description
December 2010 - CurrentGreetz BV, Amsterdam As a consultant for Sig-I/O I maintained and monitored the production environment for Greetz. Various small and big projects have been executed in the 24/7 production environment. Tasks included:
  • Upgrading / replacing routers
  • Replacing SAN
  • Virtualizing servers
  • Fully manage large outsourced IT environment running RedHat Linux, CentOS, Ubuntu, Redhat Cluster Suite, RedHat Global Filesystem, F5 Load balancers and Tomcat application servers
  • System monitoring, alerting and incident response
January 2005 - January 2011Snow BV, Geldermalsen As a consultant for Snow I have worked at many major multinational clients in the Telecommunications, Banking and Minerals sectors, maintaining complex Unix-centric environments.
April 2010 - January 2011Tele2, Diemen
  • System monitoring
  • Implementation of OpenLDAP central authentication system
  • Migration of datacenter, including virtualizing older systems, migrating to HP C-7000 blade systems
  • Maintaining EMC Networker backup environment
September 2008 - April 2010T-Systems, Den Haag
  • Migration of Tru64, Solaris, HP-UX environment to AIX 6 LPAR's and Solaris 10 Zones.
  • Designing, building, testing, implementing, maintaining and documenting OpenLDAP based central directory for the multi-vendor Unix environment (Solaris, AIX and Linux)
  • Building kickstart environment for RedHat Linux virtual machines
  • System monitoring
October 2007 - August 2008Venspro, Hoofddorp
  • System administration on Apache/Tomcat clusters, F5 Load balancer, cisco routers and firewalls.
  • Datacenter migration
  • System monitoring
Jan 2006 - September 2007Rabobank, Zeist
  • System maintenance of Solaris 8 and Checkpoint Linux systems
  • Scripting utilities for RSA-ACE server (tcl) automation
  • Incident handling on DNS, firewall and management systems
  • Migrating sudo installation to centralised LDAP-based configurations
  • Auditing systems and writing audit-checking framework and scripts to report on security related settings on Solaris 8 systems.
Apr 2006 - Dec 2006Shell E-P, Rijswijk
  • System maintenance of shells custom Linux desktop and server systems
  • Building a server, desktop, and office-frontend environment based on OpenBSD for use im embargoed countries. Environment consisted of OpenBSD, OpenOffice, Gnome, cups printing, Exim mailservers, centralised kerberos authentication, ldap, version-controled configurations (svn) and automated package-building, testing and installation.
May 2005 - Apr 2006Tele2-Versatel, Amsterdam-ZO
  • Design a centralized backup infrastructure for management systems, customer systems and broadcast systems.
  • Design and implement a configuration management system for hardware in the versatel testlab.
  • Design and implement a resource reservations/booking system on top of the configuration management system
  • Design system sub-section of Versatel's Narrowcasting product
  • Design and implement reporting, management and configuration tools for Versatel's ADSL2 Triple-Play product.
Feb-Apr 2005Gaz De France, Zoetermeer Gaz de France Netherlands has a small permanent IT department that only handled the network and windows system. It also has some Solaris servers that run it's mission critical application by Landmark Graphics. My job was to administrate these Solaris systems, migrate the Landmark software to a new release, increase performance of the Landmark systems and support the users of those systems.
The performance of the Landmark system was increased by tuning kernel parameters, moving data to different raid-arrays and setups (raid1 vs raid5), upgrading hardware and offloading applications to seperate servers or to the desktops. I also standardized a Linux desktop system for use with the Landmark application, made a plan for a new management network and remote administration system.
Nov-Dec 2004UPC, Schiphol-Rijk
(Via Cohesion)
UPC is legally required to protect it's information and have asked for assistance in installing a consistent and current version of Secure-Shell to all it's Sun Sparc (Solaris 7,8,9) based systems. An inventory of currently running SSH versions was made, applications and users using these versions were identified and a plan was written to migrate all systems to a new site-wide consistent version of Secure Shell.
A custom packaged version of OpenSSH was created, fullfilling all UPC requirements and wishes regarding it's configuration. This packaged version was then installed on UPC's systems, old settings, users and applications were migrated to the new version while maintaining availability to the users of the production systems.
May-Oct 2004Belastingdienst, Apeldoorn
(Via Syconos)
After numerous contract extensions working for the Unix department I moved to the Networking department. My jobs included:
  • Configuring Avaya, Olicom and Cisco switches and routers (Tokenring and Ethernet)
  • Writing network-management tools using expect, perl and shell scripts
  • Analyzing network problems (sniffing, routing)
2003-2004Personal Together with some (ex-)collegues I have set up a non-profit, private ISP. Together we handle all tasks a real ISP handles. We have placed a unix system/router on a AMS-IX location, setup BGP routing on IPv4 and IPv6, requested a AS-number and IP space from RIPE, setup peering with other ISP's and provide mail, usenet, web and shell access to 'sponsors/users'. We have also joined the Domain-Registry organisation, so we can request and administrate our own .nl domain named without relying on other ISP's.
More info on
Jul 2003- May 2004Belastingdienst, Apeldoorn
(Via SyConOS)
The belastingdienst (revenue service) needed temporary system administrators to assist it's personnel during a migration traject to a complete new computing environment, based on AIX. My task was to assist the local administrators and solve all incidents in the production enviroment while the local staff was on vacation or on large tutorial trajects. The department was responsible for various websites running on HP-UX and AIX systems, the network equipment (firewalls, routers, intrusion-detection, monitoring) and backups.
After several extensions of the original contract I became responsible for maintaining most of the belastingdienst's webservers and supporting systems. Performing (security) updates and performance tuning the AIX and HP systems, monitoring, IDS and logging.
2003Geestgronden, Heemstede
(Via SyConOS)
Installing MGE's ups software on Bull AIX systems
2002-2003SyConOS IT, Emmeloord Installing, testing, documenting and maintaining the company mail server, based on a SuSe linux system, running the courier-mta mail suite. The server provides SMTP, POP3, IMAP, webmail, a support website and mailinglists for the employees of SyConOS. The mailserver makes use of various encryption protocols to privide secure access to the e-mails (TLS, SSL, over either IMAP, POP3 or SMTP). Various methods are used to limit the amount of spam received on the system by using multiple RBL lists, bayesian filtering and analysis of e-mail content to discover spam.
2001-2003ABN-Amro Bank, Amsterdam
(Via SyConOS)
System administration and technical lead on security projects for the ABN-AMRO's e-Banking systems and internal unix (IBM and HP) environments. Tasks included:
  • Deciding on security enhancing facilities to implement and enforce
  • Building and testing these facilities, automating installation and configuration.
  • Documenting configuration-management system
  • Daily administration of IBM and HP server-farm (250+ nodes)
  • Implementing custom patched versions of OpenSSH, OpenSSL, SuDo
  • Supporting junior system-administrators and customers
2001VVAA, Utrecht
(Via SyConOS)
The VVAA HP server environment had been without maintenance for some time and needed a serious overhaul and checkup. VVAA wanted to give administration of these servers out to a third party service provider. Before this could be done the environment needed to be cleaned up and analysed. The following actions were undertaken so the third party could take over maintenance and administration for the HP server environment.
  • Writing planning for analysis and cleanup.
  • Doing security assesment of the systems and environment.
  • Writing 'administrative' documentation.
  • Writing security advisories.
  • Creating and documenting backup procedure HP systems (Ignite tapes)
  • Documenting problems, planning fix-actions for these problems, documenting and fixing defects.
  • Analysing performance and creating tools for gathering performance data from the HP server environment.
  • Creating trend-graphs from gathered performance-data using self-written tools.
2001ABN-Amro Bank, GTS
(Via SyConOS)
My team was responsible for managing the test environment for the GTS Portal, doing application intakes, testing their installation in the test environment, documenting these actions and helping the applications for a smooth transition to the production environment. The environment consisted of various HP-9000 systems and using (amongst others) the following software:
  • Iplanet Enterprise Server
  • Iplanet Proxy server
  • Apache webserver
  • Websphere Application server
  • SilverStream Application server
  • Silverstream E-Portal
  • Oracle 8
  • Java
The ABN's use of the Silverstream Application server on the HP 11.x platform was (one of) the first worldwide, so we encourered a lot of problems and issues with the application which we resolved in cooperation with specialists from Silverstream.
2000 - 2001ABN-Amro Bank
(Via SyConOS)
Setting up and managing various company websites on HP-UX 11 and Debian GNU/Linux.
Managing Sun Oracle8i database servers
2000ABN-Amro Bank
(Via USN and SyConOS)
Installing, managing and upgrading the production and test/development environment for ABN-Amro's new import/export portal website (The website has since been discontinued by the ABN Amro). Activities included:
  • Installing HP-UX 11.x
  • Installing Netscape/IPlanet Enterprise server
  • Installing Oracle support software (Java, ODBC)
  • Installing and managing test servers
  • Setting up monitoring system
  • Setting up backup system
  • Negotiating SLA terms for hosting
  • Performance tests / Load tests
  • Performance tuning
Other tasks included:
  • Setting up and maintaining the projects gateway/proxy and firewall systems
  • Troubleshooting and support for the unix systems and network
  • Instructing the other sysops about the unix systems.
2000Ptt-Post Mediaservice
(Via USN)
Writing action-plan, and executing consulting tasks to increase availability of HP-9000 servers. Tasks executed include: Setting up disk mirroring with HP's volume manager (LVM), setting up a dedicated backup system, updating legacy LVM configuration while maintaining full availability during office hours.
2000Ptt-Post Mediaservice
(Via USN)
Emergency restore from a crashed bootdisk on large HP-UX 10 fileserver with corrupted Legato Networker backup indexes.
1999-2000EP&R SolutionsComplete process from idea to deployment and client-consultation of a 'network-appliance like' fileserver (unix-based) for Apple MacIntosh networks
1999-2000Ptt-Post, IT-Operations
(Via USN)
Developing and implementing a web-based system for managing internal documents, procedures and instructions. A password protected system where employees of Ptt-Post can lookup and modify (if allowed) documents via a web-interface. Tasks included programming the system, installing webserver, database (MySQL) and scripting language (PHP). Entire system developed using a revision control system, and fully documented.
1999-2000Ptt-Post, IT-Operations
(Via USN)
Second and third level HP Unix support for production (500+ nodes) and test (50+ nodes) networks. Tasks include:
  • Troubleshooting: Disk crashes, server crashes, hardware errors, disk-full.
  • Account management: Creating and deleting user and application accounts, resetting passwords.
  • Software Distribution management: Installing and removing software (universally) on remote HP sites.
  • Support for application developers
  • Installation and setup for new servers
  • Setting up and maintaining server-configuration database
  • Scipting, building tools, documenting
  • Managing NIS, DNS, Bootp, Inetd configurations
  • Managing backups and restores
1999Ptt-Post, IT-Operations
(Via USN)
Executing Millenium upgrade for the 500+ node HP-UX network (Upgraded from HP-UX 9.04 to 10.20.41).
1999Ptt-Post, IT-Operations
(Via USN)
Setting up 50+ remote Legato Networker backup systems on HP-UX using HP SureStor DLT Libraries. All 50+ systems use single setup script and are fully managable from the central management site.
1998Unix Support NederlandExtending and enhancing existing web-based application written in Server Side Javascript running under Netscape SuiteSpot on a HP700 system. The system stored customer and employee information in a Informix database.
(Via USN)
Designing and installation of a proxy machine with on-demand dialing for the company internet connection. The system also had a dial-in facility so employees could connect from outside of the company and still be able to access the corporate network directly. Linux machines have been used for proxy, gateway, firewall and e-mail systems, Cisco routers and modem-pools were used for the connections.
(Via USN)
Assisting in the setting up of a redundant NT-cluster of webservers, using hardware VPN for maintenance.
1998Algemene Rekenkamer
(Via USN)
Installation and configuration of Checkpoint Firewall-1 in combination with the eSafe virusscanner so all Internet traffic was automatically scanned for virii.
1998Vermeulen & Hollandia
(Via USN)
Setting up linux e-mail server and dial-on-demand internet connection.
1998Unisource Business NetworksBuiling a web-based DNS updating program for UBN's customers allowing them to update the secondary DNS entries themselves, saving UBN's employees a lot of time and also speeding up changes. System was built to help about 1000 customers that used UBN as a DNS secondary.
1996-1997DelftNet InternetSystem administration for this small start-up ISP. Tasks range from system setup to creating web-pages and setting up accounts to doing crash-recoveries etc.


References are available on request