Unix/Linux and Network Administration, Security, especially wrt. to Internet

Migration of existing Debian clusters to new hardware, hardening of OS and application (DNS, Apache, squid, postfix, LDAP), reconfiguration of DNS servers (split resolver and authoritative, adapt to new Windows domain controllers)
Evaluation of cluster SW (heartbeat/pacemaker), Rolling upgrade of cluster members to new HW Migration from Sun iPlanet directory server to OpenLDAP, evaluation of
alternatives and user interfaces, adapt replication mechanisms and administration tools, test connectivity and function with RADIUS servers (Radiator), run performance tests for parameter fine-tuning Planning of migration steps, writing migration concepts and operational documentation for all services, presentations for operational staff and end customer, documentation according to IT-Grundschutz (BSI)

Development and Setup of a highly available web server setup based on low cost equipment for a small hosting company and other smaller projects (DNS Server migration, temperature control system for data centres with short message alarming, setup of a mail server with database authentication, web mail front end, spam and virus scanning entirely based on open source)

implement high availability on a broadcast media storage system (Omneon MediaGrid), tune performance of cluster members to 10GB/s of total traffic, instruct administrators

Planning and automated kickstart setup of several large web setups with Red Hat Enterprise Linux using Red Hat Satellite Server (Apache/Tomcat, Weblogic, Oracle RAC 11g, DNS, Mail), Consulting for System Security and Operational Procedures in these setups, Setup of a VPN tunnel infrastructure for a small consulting company

Administration of Servers, Storage and Backup (Sun, Veritas, NetBackup, HP-UX) for (another) Telco, administration of mail servers, planning and consulting on security and capacity, planning, setup and verification of a centralised, OpenLDAP-based authentication system for all Unix systems, trainings for
admin team (apache, postfix) Setup of several heartbeat clusters, Setup of Nagios monitoring (clustered)

Planning, sizing and installation of a medium-sized web server setup (20 servers) with firewalls, load balancers, FC storage and focus on high availability and low administration costs (Debian Linux OS, Apache web server, tomcat and JBoss application servers, Foundry Server Iron Load Balancer, Juniper Netscreen Firewalls, all in HA cluster configuration). Load simulation, security assessment, availability checks, creation of basic operation documents (according to ITIL processes)

Installation, upgrade and administration of Solaris, Linux, FreeBSD machines and clusters during a large internal IT restructuring project for a Telco company, migration of network management applications (HP OpenView, NetCool, InfoVista) to new systems, setup of a customised JumpStart server and development of a automated Linux install server (FAI)

Administration of a large client/server setup running Digital Unix/Tru64, OS upgrade, upgrade of TruCluster setups, migration of Digital Unix servers to Linux server clusters, adminstration of the core network components (FDDI and Ethernet), mail, web, proxy, dns servers, implementation of a
open source network management and monitoring system with nagios and cricket, development of a security concept for data center and clients together with the customer, training for the operating team by regular seminars, assistant manager of operations, Consulting on web servers, security, and internet server setups in general for the end customer during this time also Setup and securing a DNS resolver, DHCP Server and
Implementation of a internal firewall with traffic shaping abilities
(assigning bandwidth to subnets and services individually)
for an international media company

Installation of several Sun/Solaris servers incl. securing OS and
applications for internet use Setup of a Linux/IPsec based VPN between DSL dialins for testing and evaluating a VoIP solution entirely based on open source products

• Administration of a large web server setup including Load Balancers, NetApp Filer, Cisco Routers for an international customer. Also responsible for all technical communication, ressource planning and troubleshooting. SW and security consulting for customers of C&W ECRC regarding their server
  setups and networks (supporting the presales teams)
• Creation and testing of standard configurations for several unix software packages (sendmail, apache, ftp daemons, inn etc., see openpkg.org)
• Migration of the Usenet architecture to inn, including ressource planning, setup and securing the servers, migrating peers and customers
• Definition of SLAs for "Web Server Hosting" as a standard product

Health and self-written tools, performance monitoring and capacity planning, administration of the central firewall and its platform (CheckPoint FW-1 on Solaris), authoring of several documents on security, operating and management of the network, security consulting for the customer (DeTeSystem/German Telekom, now T-Systems)

This network was based on ATM and FR and operated by DeTeSystem for a customer (Finance).

during this time also

Adminstration of a "Internet Service Area" for a worldwide IP
network (CheckPoint FW-1, mail, proxy, name server, RealSecure IDS) for a German Telekom customer and
Evaluation of a IP accounting and billing SW (X-acct)

Several smaller projects for different german ISPs

planning and setup of all needed equipment (servers, routers),
administrating and securing network infrastructure, selection of upstream, contracts with upstreams and carriers, financial planning and controlling, operation, team building and training
Main customer projects include DSL services and a pan-european VPN based on Ascend (now Lucent) routers