ArunKrishna S

Senior Network and Security Engineer with 18+ years of IT experience, including 15+ years in enterprise networking and 3.5+ years in telecommunications. Proven expertise in architecting, transforming, securing, and supporting large-scale enterprise, banking, and data center environments across multi-vendor technologies. Strong hands-on capability across Cisco Enterprise, Cisco ACI, Nexus, SD-WAN, BGP/MPLS, Palo Alto, Fortinet, Cisco ISE, wireless infrastructure, and network automation.

Experienced in leading network modernization, security migration, high-availability design, lifecycle management, technical standards, and complex incident resolution with Dual CCNP Certifications.

PROFESSIONAL EXPERIENCE Senior Network Engineer | GEODIS India Aug 2024 – Present • Lead enterprise network architecture, transformation, and Tier-3 engineering across data center, WAN, security, wireless, and identity infrastructure.

• Led Cisco ASA to Palo Alto firewall migration, ensuring security policy continuity and zero production downtime.
• Designed BGP over IPSec between Fortinet and Palo Alto environments for resilient connectivity and automated failover.
• Manage Cisco ACI and Nexus 9K/7K/5K data center fabrics; lead lifecycle management and standardized code-level upgrades.
• Lead Cisco SD-WAN (Viptela) implementation, deployment, troubleshooting, and support for SD-WAN fabric and DC edge routers.
• Administer, troubleshoot and upgrade Palo Alto, Fortinet, Cisco ISE, F5 LTM/GTM, Cisco 9800/3500 WLC, and enterprise routing/switching infrastructure.
• Develop Python automation scripts and build standards; create SOPs and technical documentation to improve operational consistency.
• Drive network hardening, vulnerability remediation, and adoption of security standards across global infrastructure.

Senior Network Security

Engineer | SI2 Technologies | Client: Intuitive Surgical Jan 2024 – Jul 2024 • Supported enterprise data center and branch networks across multi-vendor routing, switching, wireless, firewall, and SD-WAN environments.

• Managed Palo Alto firewalls and Aruba Silver Peak SD-WAN; performed complex troubleshooting and software upgrades.
• Administered Aruba Clear Pass NAC, Cisco DNAC, monitoring platforms, and enterprise authentication services.
• Resolved wired and wireless incidents within SLA and coordinated with vendors for complex infrastructure issues. Oct 2022 – Jan 2024 Senior Network Administrator L3 | Wipro Technologies | Client: KLA-Tencor • Supported global data center and branch network infrastructure across US, UK, APAC, and EMEA environments.
• Managed Aruba Silver Peak SD-WAN, Aruba ClearPass NAC, Cisco ISE, Cisco DNAC, Cisco 9800 WLC, and enterprise monitoring platforms.
• Provided hands-on engineering across Arista data center switching, Cisco Nexus 9K, ASR 1000, and ISR 4000 platforms.
• Troubleshot BGP, OSPF, Layer 2/Layer 3, IPSec, and DMVPN issues; collaborated with vendors and TAC to restore services. PROFESSIONAL EXPERIENCE Network Engineer | Sify Digital Services | Client: SBI & Associate Banks Jan 2022 – Oct 2022 • Supported mission-critical banking network infrastructure and WAN connectivity across Cisco, Juniper, and Huawei platforms.
• Managed BGP/MPLS connectivity through BSNL Cloud and multiple ISP partners; performed routing, configuration, IOS, and hardware upgrades.
• Provided remote support to branch managers and staff and coordinated with ISPs, LAN vendors, and banking stakeholders for incident resolution and new branch commissioning.
• Supported network availability objectives targeting 99.99% WAN uptime and drove root-cause analysis for recurring incidents.

Network

Engineer | NTT Ltd | Client: SBI & Associate Banks Jun 2017 – Dec 2021 • Delivered engineering support for SBI CONNECT, a large-scale banking WAN program spanning branch and enterprise connectivity.

• Configured and supported Cisco, Juniper, and Huawei routers and switches; managed BGP, MPLS, leased lines, and branch network implementations.
• Performed network fault investigations, performance monitoring, firmware upgrades, configuration changes, and remote/onsite troubleshooting.
• Collaborated with network architects, BSNL MPLS/Transmission teams, and ISP partners on optimization, upgrades, and complex service restoration.
• Supported network management objectives aligned to 99.99% availability and created/updated operational knowledge documentation.

Field

Engineer | SequelOne | Client: SBI, Associate Banks & Federal Bank Jul 2014 – Jun 2017 • Supported SBI CONNECT and FEDWIDE WAN projects, including configuration, monitoring, troubleshooting, and maintenance of Cisco and Huawei infrastructure.

• Conducted feasibility studies and supported commissioning of new bank branches with telecom and ISP partners.
• Implemented and troubleshot routing, switching, OSPF, MPLS VPN/BGP, VLAN, VTP, trunking, leased-line, ISDN, and VoIP environments.
• Designed and implemented small network infrastructures and provided technical support across routing, switching, security, and VoIP.

Network Support

Engineer | CP Softech Pvt. Ltd. May 2012 – May 2014 • Administered network connectivity, Internet access, hardware, wireless access points, VLANs, inter-VLAN routing, STP/RSTP, VTP, voice VLANs, and IP phones.

• Designed and implemented small network infrastructures and performed routing table and ACL changes, upgrades, and troubleshooting. MSC Technician | Achievers Telecom Services Pvt. Ltd. | Client: Huawei Jul 2008 – Oct 2011 • Provided BSS/OSS operational support for mobile telecommunications networks, monitoring BSC/MSC/BTS alarms and coordinating incident escalation.
• Performed BSC health checks, outage reporting, alarm analysis, site integration, testing, and maintenance while supporting field and transmission engineering teams.
• Trained newly onboarded OMCR personnel and supported operational readiness across telecom network environments. MAJOR BANKING & NETWORK TRANSFORMATION HIGHLIGHTS • SBI recognition for converting primary BSNL MPLS links in Pathanamthitta District to OFC, achieving a first-of-its-kind district milestone in Kerala (March 2022).
• SBI recognition for completing NAC configuration on Cisco switches, contributing to the first district in India and Kerala to complete the initiative.
• Extensive experience supporting banking WAN infrastructure, branch connectivity, BGP/MPLS, ISP coordination, and network availability across large distributed environments