This error occurs when Node.js DNS resolution exhausts all retry attempts after receiving SERVFAIL responses from the DNS server. SERVFAIL indicates the DNS server encountered an error and could not process the query, typically due to zone misconfiguration, DNSSEC validation failures, or temporary server problems.
The "DNS SERVFAIL with all try again responses" error means that Node.js attempted to resolve a hostname multiple times, but each attempt returned a SERVFAIL response from the DNS server. SERVFAIL (Server Failure) is a DNS response code indicating that the DNS server encountered an internal error and could not process the query successfully. Unlike ENOTFOUND (which means the domain doesn't exist) or timeout errors (where the server doesn't respond at all), SERVFAIL means the server is responding but explicitly reporting it cannot resolve the query. Node.js will retry DNS lookups several times when it receives SERVFAIL responses, hoping the server recovers. After all retries return SERVFAIL, the error is propagated to your application. The root cause is typically on the DNS server side—it could be a misconfigured zone file, DNSSEC validation failures, server overload, or temporary outage. This indicates a problem with the DNS infrastructure serving the domain, not with your network connectivity or Node.js configuration.
Confirm the error is actually SERVFAIL by querying DNS directly:
# Query with dig to see the full response
dig example.com
# Look for the status line - it should show "status: SERVFAIL"
# Example output:
# ; <<>> DiG 9.16.1-Ubuntu <<>> example.com
# ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 12345
# Try querying with a specific DNS server
dig @8.8.8.8 example.com
dig @1.1.1.1 example.com
# Check if recursive queries work
dig +trace example.comIf dig shows SERVFAIL, the problem is definitely with DNS resolution, not your Node.js code.
Investigate the authoritative DNS setup for the domain:
# Find the authoritative nameservers
dig example.com NS
# Check what nameservers are responsible
nslookup -type=NS example.com
# Query the authoritative server directly
dig @ns1.example.com example.com
# Check for DNSSEC records
dig example.com +dnssec
# Validate DNSSEC if enabled
dig example.com +dnssec +trusted-adIf the authoritative servers also return SERVFAIL, the issue is on the DNS provider's side. Contact the domain's DNS hosting provider or administrator.
Test if the problem is specific to one DNS resolver:
# Test with Google DNS
dig @8.8.8.8 example.com
dig @8.8.4.4 example.com
# Test with Cloudflare DNS
dig @1.1.1.1 example.com
dig @1.0.0.1 example.com
# Test with Quad9 (privacy-focused)
dig @9.9.9.9 example.com
# Test with your ISP's DNS (usually in /etc/resolv.conf)
dig @<ISP_DNS_IP> example.comIf all public DNS servers show SERVFAIL, the problem is definitely on the authoritative server. If only one shows SERVFAIL, that resolver may have issues.
Change your system DNS to a reliable public resolver while the issue is being fixed:
On Linux (systemd-resolved):
# Edit the resolver configuration
sudo nano /etc/systemd/resolved.conf
# Set these DNS servers
[Resolve]
DNS=8.8.8.8 8.8.4.4 1.1.1.1 1.0.0.1
FallbackDNS=8.8.8.8 8.8.4.4
# Restart the service
sudo systemctl restart systemd-resolved
# Verify the change
systemd-resolve --statusOn macOS:
# Set DNS servers for your primary connection
sudo networksetup -setdnsservers Wi-Fi 8.8.8.8 8.8.4.4 1.1.1.1
# Verify
networksetup -getdnsservers Wi-Fi
# Flush DNS cache
sudo dscacheutil -flushcacheOn Windows (PowerShell as Administrator):
# Get the network adapter index
Get-NetAdapter | Where-Object {$_.Status -eq "Up"}
# Set DNS (replace "Ethernet" with your adapter name)
Set-DnsClientServerAddress -InterfaceAlias "Ethernet" -ServerAddresses ("8.8.8.8","8.8.4.4","1.1.1.1")
# Verify
Get-DnsClientServerAddress -InterfaceAlias "Ethernet"
# Flush cache
ipconfig /flushdnsAdd retry handling in your Node.js code to gracefully handle SERVFAIL responses:
const https = require('https');
const dns = require('dns').promises;
async function makeRequestWithDnsRetry(hostname, maxRetries = 3, baseDelay = 1000) {
for (let attempt = 1; attempt <= maxRetries; attempt++) {
try {
console.log(`Attempt ${attempt}: Resolving ${hostname}...`);
// Try DNS resolution
const address = await dns.resolve4(hostname);
console.log(`✅ Resolved ${hostname} to ${address[0]}`);
// DNS succeeded, make the HTTP request
return new Promise((resolve, reject) => {
const options = {
hostname: hostname,
port: 443,
path: '/',
method: 'GET'
};
const request = https.request(options, (res) => {
let data = '';
res.on('data', chunk => data += chunk);
res.on('end', () => resolve({ status: res.statusCode, body: data }));
});
request.on('error', reject);
request.end();
});
} catch (err) {
console.error(`❌ Attempt ${attempt} failed:`, err.message);
if (attempt < maxRetries) {
const delay = baseDelay * Math.pow(2, attempt - 1);
console.log(` Retrying in ${delay}ms...`);
await new Promise(resolve => setTimeout(resolve, delay));
} else {
throw new Error(`DNS resolution failed after ${maxRetries} attempts: ${err.message}`);
}
}
}
}
// Usage
makeRequestWithDnsRetry('example.com')
.then(result => console.log('Success:', result))
.catch(err => console.error('Failed:', err.message));Implement DNS caching to avoid hammering a problematic DNS server:
npm install cacheable-lookupconst https = require('https');
const http = require('http');
const CacheableLookup = require('cacheable-lookup');
// Create cacheable DNS resolver
const cacheable = new CacheableLookup({
maxTtl: 300, // Cache for 5 minutes
minTtl: 0, // No minimum cache time
errorTtl: 0.1 // Cache errors for 100ms (short, to retry quickly on SERVFAIL)
});
// Install globally for all HTTP/HTTPS requests
cacheable.install(http.globalAgent);
cacheable.install(https.globalAgent);
// Now all requests benefit from DNS caching
https.get('https://example.com', (res) => {
console.log('Request completed with cached DNS');
});Report the SERVFAIL issue to the appropriate party:
If you own the domain:
- Log into your DNS hosting provider (Route 53, Cloudflare, GoDaddy, etc.)
- Check the zone file for errors or invalid records
- Verify all nameserver delegations are correct
- Check the DNSSEC configuration if enabled
- Consider running a zone validation tool like:
dig example.com ANY
dnsviz example.com # Online tool for DNSSEC visualization- Temporarily disable DNSSEC if enabled (may be the cause)
- Contact your DNS provider's support if the zone file looks correct
If it's a third-party domain you depend on:
- Report the issue to the domain owner
- Provide evidence: dig output showing SERVFAIL
- Ask them to check their DNS provider's status page
- Request an ETA for resolution
For production applications, implement proper error handling and monitoring:
const dns = require('dns').promises;
// Custom error handling for DNS
async function resolveWithFallback(hostname, fallbackIp = null) {
try {
const addresses = await dns.resolve4(hostname);
return addresses[0];
} catch (err) {
if (err.code === 'SERVFAIL') {
console.error(`DNS SERVFAIL for ${hostname}`);
// Send alert to monitoring system
await sendAlert({
type: 'DNS_SERVFAIL',
hostname: hostname,
timestamp: new Date()
});
// Use fallback IP if available
if (fallbackIp) {
console.warn(`Using fallback IP: ${fallbackIp}`);
return fallbackIp;
}
}
throw err;
}
}
// Health check for critical DNS names
async function monitorCriticalDomains() {
const criticalDomains = ['api.example.com', 'cdn.example.com'];
setInterval(async () => {
for (const domain of criticalDomains) {
try {
await dns.resolve4(domain);
console.log(`✅ ${domain}`);
} catch (err) {
console.error(`❌ ${domain}: ${err.message}`);
// Trigger PagerDuty alert, Slack notification, etc.
}
}
}, 60000); // Check every minute
}
monitorCriticalDomains();Understanding DNS Response Codes
When a DNS query fails, the server returns a response code (RCODE):
- NOERROR (0): Success
- FORMERR (1): Format error in the query
- SERVFAIL (2): Server failure - can't process the query
- NXDOMAIN (3): Non-existent domain
- NOTIMP (4): Not implemented
- REFUSED (5): Query refused by policy
SERVFAIL specifically means the DNS server encountered an error while trying to process your query. This can happen at various stages of DNS resolution.
DNSSEC and SERVFAIL
If DNSSEC is enabled on a domain, SERVFAIL often indicates a DNSSEC validation problem:
# Check if DNSSEC is enabled
dig example.com +dnssec | grep -i "ad\|validating"
# Get detailed DNSSEC diagnostic info
dig example.com +dnssec +cd | head -20Common DNSSEC issues causing SERVFAIL:
- Expired DNSKEY records
- Broken chain of trust between zones
- Incorrect DS (Delegation Signer) records
- NSEC3 misconfiguration
- Signature expiration
If you see DNSSEC-related SERVFAIL, contact your DNS provider to fix the zone signing.
DNS Query Tracing
To see the exact point where DNS resolution fails:
# Full trace of DNS resolution path
dig +trace example.com
# Verbose output showing each query
dig example.com +short
dig example.com +norecurse # Query your ISP's resolver
# Check specific nameserver responses
for ns in $(dig example.com NS +short | grep -o "ns[0-9].example.com"); do
dig @$ns example.com
doneNode.js DNS Debugging
Enable detailed DNS logging in Node.js:
NODE_DEBUG=dns,http node app.js 2>&1 | grep -A5 SERVFAILThis shows:
- Which DNS servers are being queried
- Response codes from each attempt
- Retry logic and backoff timing
Resolver Configuration on Linux
The /etc/resolv.conf file controls DNS resolution:
# View current configuration
cat /etc/resolv.conf
# Key options:
# nameserver - DNS server IP address (up to 3)
# timeout - Wait time for each query (default 5s)
# attempts - Number of retries (default 2)
# options - Additional behavior (e.g., ndots:1)
# Example:
nameserver 8.8.8.8
nameserver 8.8.4.4
options timeout:2 attempts:3On modern systemd systems, edit /etc/systemd/resolved.conf instead.
When SERVFAIL is Not Your Problem
Sometimes you may see SERVFAIL in logs but your application works fine because:
- Your retry logic works and subsequent attempts succeed
- You've implemented DNS caching (the cached response is used)
- You have DNS fallback configured
- The SERVFAIL is transient and clears within seconds
Focus on whether your application actually fails (can't recover) vs. just logging errors. Transient SERVFAIL responses are often handled automatically by well-designed retry logic.
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