All ports
Port90/UDP
dnsixPort
90
Protocol
UDP
Category
Well-Known
Service
dnsix
What is port 90?
Port 90/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the dnsix service.
DNSIX Securit Attribute Token Map
Useful commands
nmapnmap -p 90 -sV example.comnetcatnc -zv example.com 90curlcurl -v http://example.com:90/telnettelnet example.com 90bash(echo > /dev/udp/example.com/90) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 90/udpDeny
sudo ufw deny 90/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 90 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 90 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=90/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 90" dir=in action=allow protocol=UDP localport=90Security Risks
- DNS cache poisoning attacks
- DDoS amplification using open DNS resolvers
- Information disclosure of internal subdomains
- Domain hijacking if DNS server is misconfigured
Frequently Asked Questions
What service runs on port 90/UDP?
Port 90/UDP is associated with the dnsix service. DNSIX Securit Attribute Token Map
Is it safe to expose port 90 to the Internet?
It depends on the service and configuration. Port 90 (dnsix) is a Well-Known port. If you need to expose it, keep the service updated, use strong authentication, and configure a firewall. It's always recommended to restrict access by IP when possible.
How do I check if port 90 is open?
You can use nmap: `nmap -p 90 -sV example.com`, netcat: `nc -zv example.com 90`, or the bash command: `(echo > /dev/udp/example.com/90) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 90 on my firewall?
On Linux with UFW: `sudo ufw allow 90/udp` (open) or `sudo ufw deny 90/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 90 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 90" dir=in action=allow protocol=UDP localport=90`.
What applications and services use port 90?
Port 90/UDP is used by the dnsix service. Specific uses depend on the software and configuration. Check our related tools section for more information.