Overview of the Problem
If you've encountered DNS issues while using strongSwan on Pop!_OS 21.10, you're not alone. Many users face challenges when setting up VPNs, particularly when it comes to DNS resolution. Below is the original code snippet that users often struggle with:
# Original Configuration Example
conn myvpn
right=myvpnserver.com
rightsubnet=0.0.0.0/0
auto=start
In this code, users may notice that DNS queries are not being properly routed through the VPN, leading to connectivity issues.
Understanding the Issue
When using strongSwan for VPN connections, DNS resolution can be problematic. The VPN can encrypt your connection and reroute traffic, but if the DNS requests are not properly configured, they may still attempt to resolve through your local DNS servers instead of the VPN’s DNS servers. This can result in websites and services being unreachable while the VPN is active.
Common Causes of DNS Issues:
- Local DNS Settings: If your system's DNS settings are not updated to point to the VPN's DNS servers, you may experience resolution failures.
- IPSec Configuration: Incorrect configuration of the strongSwan IPSec settings can lead to improper handling of DNS queries.
- NetworkManager Interference: Sometimes, the NetworkManager service on Linux can interfere with VPN DNS settings.
Step-by-Step Guide to Fix DNS Issues with strongSwan
1. Edit strongSwan Configuration
First, you’ll want to modify your strongSwan configuration file, typically located at /etc/ipsec.conf. Ensure that your configuration looks something like this:
config setup
charonstart=yes
syslogdir=/var/log
uniqueids=no
conn myvpn
right=myvpnserver.com
rightsubnet=0.0.0.0/0
leftsourceip=%config
auto=start
# Add the following lines for DNS
rightdns=8.8.8.8
rightdns=8.8.4.4
Adding rightdns points the DNS queries to Google's public DNS servers as an example.
2. Update /etc/resolv.conf
You will want to ensure that your DNS configuration file is appropriately set up. Open the /etc/resolv.conf file:
sudo nano /etc/resolv.conf
Ensure it contains:
nameserver 8.8.8.8
nameserver 8.8.4.4
You can also use the DNS servers provided by your VPN provider if available.
3. Restart strongSwan
After updating the configuration, you must restart strongSwan to apply the changes:
sudo systemctl restart strongswan
4. Verify Connectivity
Once you have made these changes, you can verify whether your DNS is working correctly through the VPN:
dig example.com
If you see results that don’t return your local ISP's DNS but instead show the public IP related to your VPN, your configuration is successful!
Additional Considerations
-
Firewall Settings: Make sure that your firewall settings allow traffic on the necessary ports used by strongSwan (e.g., UDP port 500 and 4500).
-
Test with Different DNS Providers: Sometimes switching to different DNS servers can resolve connectivity issues. Cloudflare’s DNS (1.1.1.1 and 1.0.0.1) is another great alternative.
Conclusion
Solving DNS issues with strongSwan on Pop!_OS 21.10 may require a few configuration tweaks, but by following the steps outlined above, you can ensure that your DNS queries are handled properly while connected to your VPN.
Understanding and resolving these issues not only enhances your online privacy but ensures a smoother internet experience.
Useful Resources
By optimizing your DNS settings and ensuring your VPN connection is appropriately configured, you can enjoy secure and reliable access to the internet.
