Alexandros Papakostas

Experience

• 

  AT&T

  Sept 2011 - Mar 2024

  - Advanced troubleshooting of network and network security issues- Configuration - VPN, Firewall Policy, Static & Dynamic Routing, Patch & OS Upgrade installation on Stand alone or High-Availability cluster devices- Implementing changes on NextGen Firewalls (Checkpoint, Fortigate, Cisco ASA / Firepower, Palo Alto)- Enforcing security policies using Zscaler to ensure and protect customer's sensitive data- Conferences and live troubleshooting/captures with customer on various issues Show less - Troubleshooting and progression of faults affecting high - end MPLS solutions (PER - CER)- Provided guidance to network operation and maintenance analysts, technicians, and/or engineers.- Perform technical analysis of complex software, hardware, and transmission facilities using various diagnostic tools in support of efficient network operations.- Working knowledge of local provider's infrastructure; i.e. SDH, microwave, DACS- Focal point for other teams within AT&T- Provided training, guidance and assistance to other Tier 1 membersTechnologies used:- Frame Relay, Ethernet- MPLS troubleshooting (L3VPN, L2VPN, Fundamentals of VPLS)- QoS troubleshooting on PER and CER Show less

  • Cyber Security Specialist

    Dec 2018 - Mar 2024

  • Network Specialist

    Nov 2015 - Dec 2018

  • Network Analyst

    Aug 2013 - Nov 2015

  • Computer Network Analyst

    Sept 2011 - Jul 2013
• 

  LTIMindtree

  Mar 2024 - Jun 2024

  Senior Network Engineer

  - Working as contractor for Microsoft- Deployment of new hardware devices in Microsoft's datacenters supporting Microsoft Azure Cloud- Installation and configuration of Cisco IOS XR, Juniper and Arista routers- Ensured seamless integration of new hardware into existing network infrastructure- Testing and validation of network configurations to ensure optimal performance and security

• 

  NTS Netzwerk Telekom Service AG

  Sept 2024 - now

  Service Engineer