brandid Ltd SystemsNetwork Administrator
Feb. 2002 - Mar. 2006Working for an ISP, responsible for low-level network infrastructure of client facing production systems. Duties included implementing & maintaining high availability, load balancing, business continuity, routing protocols, VPN's, backup/restoration, disaster recovery, clustered file systems, hardware roll out, IP security, layer 7 content filtering and restriction (smtp/spam, http, intrusion detection etc.) IP address allocation, DNS, mail forwarding. Responsible for building the companies first RedHat Linux web cluster which included two load balancers/routers/firewalls which fed multiple SuSE & RedHat Linux web servers & Macromedia Communication Servers which provided video conferencing, real time chat & VOIP services. The whole cluster was spread over two data centres for the sake on high availability, I created many shell scripts which synced data between the web servers such as uploaded files, LDAP authentication database and DNS zone files. I created a shell script on the directors, which provided the IP failover so if one unit went down the other took on the IP's of the failed unit and continued to serve. I was responsible for securing all aspects of the systems including configuring and maintaining firewall policies (Mainly Linux/Iptables). I had to maintain more than one routing table on many of the web servers for failover of the load balancers. I had to setup an alerting/monitoring/logging system using a combination of Zabbix, SNMP & MRTG, which monitored every cluster member, ensuring that the SLA was maintained & alerts where distributed when a failure was detected 24x7. All system builds were documented which was subject to change control, I had to perform upgrades/changes according to change requests and fulfil the change control policy. I was I involved many projects, one of which was the relocation of the entire cluster to another provider/data centres whilst maintaining 100% uptime