Introduction
SmartDNS is a powerful local DNS server that improves network performance by selecting the fastest IP from multiple upstream DNS servers. It supports secure DNS protocols such as DoT (DNS over TLS) and DoH (DNS over HTTPS), ensuring privacy while preventing DNS pollution. Additionally, SmartDNS integrates high-performance ad filtering, making it an ideal choice for optimizing home or enterprise networks.
This article explores the SmartDNS project, focusing on its integration with OpenWrt, a popular open-source router firmware. By leveraging SmartDNS, OpenWrt users can significantly enhance their network efficiency and security.
SmartDNS Architecture:
- SmartDNS receives DNS query requests from local network devices, such as PCs and mobile phone query requests.
- SmartDNS sends query requests to multiple upstream DNS servers, using standard UDP queries, non-standard port UDP queries, and TCP queries.
- The upstream DNS server returns a list of Server IP addresses corresponding to the domain name. SmartDNS detects the fastest Server IP with local network access.
- Return the fastest accessed Server IP to the local client.
Why Choose SmartDNS for OpenWrt?
OpenWrt provides extensive customization options for routers, making it a preferred choice for networking enthusiasts. However, its default DNS resolver, Dnsmasq, uses an all-servers approach, returning the first response received rather than the fastest. SmartDNS addresses this limitation by selecting the optimal IP for each request, improving speed and reliability.
Key Advantages:
- Optimized DNS Performance: SmartDNS queries multiple upstream DNS servers and returns the fastest response.
- Enhanced Privacy: Supports DoT and DoH, protecting users from DNS snooping and manipulation.
- Robust Ad Filtering: Blocks unwanted domains to enhance browsing experience.
- Low Resource Consumption: Utilizes multi-threaded asynchronous I/O for high efficiency.
- Flexible Client Management: Allows per-client query control based on MAC and IP addresses.
Installing SmartDNS on OpenWrt
Setting up SmartDNS on OpenWrt is straightforward. Follow these steps to install and configure it for optimal performance.
Step 1: Install SmartDNS
To install SmartDNS on OpenWrt, run the following command in the terminal:
opkg update && opkg install smartdns
This command updates the package list and installs SmartDNS.
Step 2: Configure SmartDNS
After installation, configure SmartDNS by editing its configuration file:
nano /etc/smartdns/smartdns.conf
Add or modify the following lines to define upstream servers and enable secure DNS protocols:
server 8.8.8.8 -tls
server 1.1.1.1 -tls
server 9.9.9.9 -https
Save the file and restart the SmartDNS service:
/etc/init.d/smartdns restart
Step 3: Set SmartDNS as the Default Resolver
To ensure OpenWrt uses SmartDNS as the primary resolver, modify the Dnsmasq configuration:
nano /etc/config/dhcp
Replace the existing DNS settings with:
option noresolv '1'
option server '127.0.0.1#53'
Restart Dnsmasq for changes to take effect:
/etc/init.d/dnsmasq restart
SmartDNS Features and Benefits
Multiple Virtual DNS Servers
SmartDNS supports multiple virtual DNS servers, each with different ports and rules. This feature enables advanced network segmentation and policy enforcement.
High-Performance Query Processing
With its multi-threaded architecture, SmartDNS efficiently handles large query loads without performance degradation.
Support for Multiple Query Protocols
SmartDNS supports UDP, TCP, DoT, and DoH, ensuring maximum flexibility in DNS query handling.
Ad Filtering and Malicious Domain Blocking
Users can define domain filtering rules to block ads and malicious websites, improving security and browsing experience.
Dual-Stack IPv4 and IPv6 Support
SmartDNS fully supports both IPv4 and IPv6, ensuring seamless operation in modern network environments.
DNS Forwarding and Integration with Firewall Rules
SmartDNS allows domain-based DNS forwarding and integration with ipset and nftables for advanced firewall configurations.
Troubleshooting Common Issues
Issue 1: SmartDNS Service Not Starting
Solution: Ensure that the configuration file syntax is correct. Run:
/etc/init.d/smartdns restart
logread -e smartdns
Check logs for errors and correct any misconfigurations.
Issue 2: DNS Queries Are Slow
Solution: Verify that upstream servers are responding quickly. Run:
smartdns -t
This command tests configured servers and highlights any latency issues.
Issue 3: Websites Still Show Ads Despite Filtering
Solution: Confirm that the filtering rules are correctly defined in the configuration file. Update blocklists if necessary.
Conclusion
SmartDNS is a powerful tool for enhancing OpenWrt’s DNS performance, security, and privacy. By installing and configuring SmartDNS, users can experience faster web access, better privacy protection, and improved network stability. With features such as multiple virtual DNS servers, advanced query control, and ad filtering, SmartDNS is a valuable addition to any OpenWrt-powered router.
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