Senior Network Administrator

Job Description

Position: Network & Systems Administrator

Department: IT / Infrastructure

Employment Type: Full-Time

Location: Karnal, Haryana

About the Role

We are looking for an experienced Network & Systems Administrator to manage and maintain our server, network, data center, security, domain, DNS, SSL, SMSC, and office IT infrastructure.

The ideal candidate should have strong hands-on experience in Windows & Linux server administration, networking, DNS/domain management, firewalls, SSL/TLS, VPN, routing, data center infrastructure, SMSC/SMPP, monitoring, and disaster recovery.

Key Responsibilities

1. Server Administration

* Manage and maintain Windows and Linux servers across data centers in India, the US, and other locations.

* Handle server installation, configuration, patching, upgrades, troubleshooting, and performance monitoring.

* Monitor CPU, RAM, disk usage, uptime, services, system health, and logs.

* Identify and resolve server and operating-system-related issues.

2. Network & Data Center Management

* Manage networking infrastructure including public/private IPs, routing, NAT, DNS, VPN, switches, routers, gateways, and connectivity.

* Coordinate with data centers, ISPs, hosting providers, and cloud partners for infrastructure-related issues.

* Troubleshoot network latency, packet loss, routing, connectivity, and port-related issues.

* Maintain network availability and infrastructure performance.

3. Domain, DNS & Traffic Routing

* Manage company domains, subdomains, DNS records, nameservers, and domain configurations.

* Configure and maintain A, CNAME, MX, TXT, SRV, and other DNS records.

* Manage domain-to-server/IP routing across multiple servers and data centers.

* Configure traffic routing, redirects, reverse proxies, load balancing, and failover routing where required.

* Maintain accurate mapping of domains, applications, servers, and IP addresses.

4. SSL/TLS Certificate Management

* Procure, install, configure, renew, and monitor SSL/TLS certificates.

* Manage wildcard, single-domain, and multi-domain certificates.

* Troubleshoot SSL handshake, certificate chain, SNI, protocol, cipher, and HTTPS-related issues.

* Maintain a certificate inventory and ensure timely renewals before expiry.

5. Firewall & Infrastructure Security

* Configure and maintain firewalls, security policies, port access, IP whitelisting/blacklisting, NAT, and VPN rules.

* Manage antivirus, endpoint protection, and operating-system security updates.

* Monitor unauthorized access attempts and infrastructure security incidents.

* Regularly review server exposure and security configurations.

6. SMSC / SMPP Infrastructure

* Manage and monitor SMSC servers and related infrastructure.

* Handle SMPP connectivity, SMS routing, IP/port configurations, throughput, and connectivity issues.

* Troubleshoot operator and aggregator connectivity.

* Coordinate with telecom operators and third-party telecom partners when required.

7. Software & System Maintenance

* Install, configure, upgrade, and maintain server-level software and services.

* Manage system services, scheduled jobs, dependencies, and application-supporting infrastructure.

* Perform preventive maintenance.

* Troubleshoot OS, software, service, and infrastructure issues.

8. Backup & Disaster Recovery

* Manage scheduled server, database/configuration, and infrastructure backups as applicable.

* Periodically verify backup integrity and restoration procedures.

* Maintain disaster recovery and infrastructure restoration procedures.

* Participate in recovery activities during infrastructure failures.

9. Office IT Infrastructure

* Manage office internet, LAN/Wi-Fi, firewalls, networking equipment, systems, printers, and related IT infrastructure.

* Manage primary and backup ISP connectivity where applicable.

* Troubleshoot employee system, network, internet, and connectivity issues.

* Support day-to-day office IT requirements.

10. Monitoring & Incident Management

* Proactively monitor critical servers, domains, SSL certificates, services, storage, network connectivity, and infrastructure availability.

* Respond to production and infrastructure incidents promptly.

* Investigate root causes and implement preventive measures.

* Coordinate with hosting providers, ISPs, data centers, telecom partners, and third-party vendors during incidents.

* Maintain incident and resolution records.

11. Access & Credential Management

* Manage server, VPN, firewall, domain, DNS, and infrastructure-level access.

* Implement appropriate role-based access controls.

* Ensure timely removal of access for former employees, vendors, and third parties.

* Maintain secure handling of administrative accounts and infrastructure credentials.

12. Infrastructure Documentation

* Maintain updated documentation covering:

* Servers and server inventory

* IP addresses

* Domains and DNS

* SSL certificates

* Firewall rules

* Network architecture

* Data centers

* SMSC/SMPP configurations

* Vendors and escalation contacts

* Maintain network diagrams and domain-to-server mapping.

* Ensure infrastructure documentation remains accurate and up to date.

Required / Preferred Skills

* Windows Server Administration

* Linux Administration

* TCP/IP Networking

* DNS & Domain Management

* SSL/TLS & SNI

* Routing & NAT

* VPN

* Firewall Management

* Reverse Proxy

* Load Balancing

* Server & Network Security

* Antivirus / Endpoint Security

* Data Center Management

* SMSC / SMPP

* Backup & Disaster Recovery

* Infrastructure Monitoring

* Office IT Support

* Troubleshooting & Incident Management

* Vendor / ISP / Data Center Coordination

Ideal Candidate

* Strong hands-on experience managing servers, networks, domains, DNS, SSL, firewalls, and data center infrastructure.

* Comfortable handling production infrastructure and critical incidents.

* Strong troubleshooting and problem-solving skills.

* Ability to work independently and take ownership of infrastructure operations.

* Good documentation and communication skills.

* Willingness to coordinate with internal teams and external infrastructure, hosting, ISP, and telecom vendors.

Key Performance Areas

* Infrastructure uptime and availability

* Incident response and resolution time

* Server and network performance

* Security and access management

* SSL/DNS/domain continuity

* Backup and disaster recovery readiness

* Infrastructure documentation accuracy

* Vendor and service-provider coordination