SERVER
SECURITY
From firewalls and SSH hardening to DNS protection and intrusion detection — everything you need to lock down your server infrastructure.
01
Server Firewall Explained
What It Does
A server firewall sits between your server and the internet — silently filtering every connection before it ever touches your system.
A server firewall acts as a protective barrier between a server and external networks.
The firewall monitors incoming and outgoing traffic and blocks connections that violate security rules.
This protection helps prevent unauthorized access attempts, vulnerability scans, and malicious network activity.
Key Defenses
- Inbound traffic filtering
- Outbound rule enforcement
- Vulnerability scan blocking
- Malicious connection drops
02
Protecting SSH Access
High-Value Target
SSH gives direct command-line access to your entire server — attackers run automated bots 24/7 trying to brute-force SSH credentials.
Secure Shell (SSH) is commonly used by administrators to remotely manage servers.
Because SSH provides direct system access, attackers frequently attempt to compromise SSH credentials.
Protecting SSH access involves restricting login attempts, disabling password authentication, and monitoring access activity.
Key Defenses
- Login attempt rate limiting
- Password auth disabled
- SSH key-only authentication
- Access activity monitoring
03
DNS Attack Prevention
Silent Risk
DNS hijacking can silently redirect your visitors to fake versions of your site — without any visible sign that anything is wrong.
Domain Name System (DNS) infrastructure plays a critical role in internet communication.
DNS attacks such as spoofing, cache poisoning, and hijacking can redirect users to malicious websites or disrupt service availability.
Protecting DNS infrastructure requires monitoring DNS traffic and implementing authentication mechanisms.
Key Defenses
- DNS traffic monitoring
- DNSSEC authentication
- Cache poisoning prevention
- Hijacking detection
04
Server Intrusion Detection
Why It Matters
Most server breaches go undetected for weeks — intrusion detection systems catch the behavioral signs that antivirus tools miss.
Intrusion detection systems monitor server activity to identify suspicious behavior that may indicate an ongoing attack.
These systems analyze network traffic, system logs, and user activity to detect unauthorized access attempts.
Early detection allows administrators to respond quickly and prevent further compromise.
Key Defenses
- Network traffic analysis
- System log monitoring
- User activity tracking
- Rapid alert & response
05
Hardening Linux Servers
Security Baseline
Every unused service running on a Linux server is a potential attack vector — hardening means closing every door you're not using.
Linux server hardening involves applying security configurations that reduce the attack surface of a system.
This includes disabling unnecessary services, enforcing access control policies, updating software components, and monitoring system activity.
A hardened server environment significantly reduces the risk of compromise.
Key Defenses
- Disable unused services
- Access control enforcement
- Regular software updates
- Continuous activity monitoring
Next Topic
Spam ProtectionREADY TO
FIGHT BACK?
Request a free demo and see Bitss in action across all five security layers — or get a custom quote for your organization.