Device names not showing in NextDNS dashboard with ASUS Merlin + CLI (setup-router=false)

Update – dnsmasq + NextDNS CLI hostname issue

Quick update after further testing. I am not restating the full setup, only what was tested and observed.

Current setup (unchanged)

• ASUS Merlin router
• dnsmasq is actively used (DHCP + local overrides)
• NextDNS CLI runs on 127.0.0.1:5555
• dnsmasq forwards to:
  server=127.0.0.1#5555
• Key options: add-mac add-subnet=32,128 report-client-info=true discovery-dns=192.168.50.1

---

What is confirmed working

• Client IPs are correctly visible in NextDNS logs
  (192.168.50.x is preserved)
• Local PTR resolution works via dnsmasq:
  nslookup 192.168.50.112 127.0.0.1→ correct hostname returned

This confirms:

• DHCP leases are correct
• dnsmasq hostname resolution is working

---

The issue

NextDNS still shows devices as:

Device #XXXX instead of hostnames.

So:

• IP is known
• PTR works locally
• but hostname is not used by NextDNS

---

Tests performed

1. discovery-dns

• Tested with:
  • 127.0.0.1
  • 192.168.50.1
  • with and without :53
• No change

---

2. dnsmasq validation

Confirmed active config:
no-resolv server=127.0.0.1#5555 add-mac add-subnet=32,128
dnsmasq forwarding is correct.

---

3. Diversion / Skynet

• Fully disabled (no iptables hooks, no dnsmasq modifications)

No change.

---

4. mDNS

• Tested both enabled and disabled

No change.

---

5. hardened-privacy

• Tested true / false

No effect.

---

6. detect-captive-portals

• Enabled / disabled

No effect.

---

7. setup-router=true (important observation)
When enabling:
setup-router=true
Device names appear correctly.

However:

• It overrides router DNS behavior
• Breaks dnsmasq-based setup

So it is not usable in this architecture.

---

Key observation

dnsmasq can resolve:
IP → hostname (PTR)
But NextDNS CLI does not seem to use that information, even with:
discovery-dns<br>report-client-info=true<br>

---

Question

In a dnsmasq-forwarded setup (setup-router=false):

How is NextDNS expected to obtain hostnames for local clients?

Is PTR lookup for private IP ranges (192.168.x.x) supported or intentionally skipped?

---

Goal

Keep:

• dnsmasq as primary resolver (for local overrides)

While:

• using NextDNS as upstream
• and still getting proper device hostnames

---

Any clarification or working example with this setup would be appreciated.

Solved with help of ChatGPT.

---

🎯 Goal

Make all of these work together:

• dnsmasq (primary resolver)
• Diversion
• Skynet
• custom DNS overrides
• NextDNS (DoH + logs)
• device names in NextDNS (NOT Device #XXX)

---

❌ Problem

When enabling:

nextdns run -setup-router

NextDNS rewrites:

/jffs/scripts/dnsmasq.postconf

and injects:

exit 0

This breaks:

• custom address rules
• Diversion
• ipset logic

---

🧠 Root Cause

NextDNS keeps original script after:

## NextDNS END

BUT:

exit 0

stops execution.

---

✅ Solution

1. Enable router mode

/jffs/nextdns/nextdns.init

Change:

cmd="$exe run"

to:

cmd="$exe run -setup-router"

---

2. Use init (NOT manual run)

/jffs/scripts/services-start

should contain:

/jffs/nextdns/nextdns.init start

---

3. Create patch script

/jffs/scripts/patch_nextdns_dnsmasq_postconf.sh

#!/bin/sh

POSTCONF="/jffs/scripts/dnsmasq.postconf"

[ -f "$POSTCONF" ] || exit 0

awk '
BEGIN { done=0 }
/^[[:space:]]*exit 0[[:space:]]*$/ && done==0 {
print " # exit 0 # disabled by local NextDNS patch"
done=1
next
}
{ print }
' "$POSTCONF" > /tmp/dnsmasq.postconf.patched && mv /tmp/dnsmasq.postconf.patched "$POSTCONF"

sed -i 's|^echo "server=127\.0\.0\.1#5555"|# disabled by patch: echo "server=127.0.0.1#5555"|' "$POSTCONF"
sed -i 's|^echo "add-mac"|# disabled by patch: echo "add-mac"|' "$POSTCONF"
sed -i 's|^echo "add-subnet=32,128"|# disabled by patch: echo "add-subnet=32,128"|' "$POSTCONF"

chmod +x "$POSTCONF"

---

4. Hook patch into init

Add AFTER:

$cmd &
echo $! > "$pid_file"

(
sleep 10

for i in 1 2 3 4 5; do
if grep -q "Configuration generated by NextDNS" /jffs/scripts/dnsmasq.postconf 2>/dev/null; then
break
fi
sleep 2
done

/jffs/scripts/patch_nextdns_dnsmasq_postconf.sh
service restart_dnsmasq
) &

---

🧪 Result

server=127.0.0.1#5342
add-mac
add-subnet=32,128
address=/your.domain/192.168.x.x
conf-file=/opt/share/diversion/list/blockinglist.conf

---

✅ Outcome

• ✔ Device names working
• ✔ Diversion working
• ✔ Skynet working
• ✔ Custom overrides working
• ✔ Survives reboot

---

⚠️ Note

With add-mac:

• NextDNS shows device names instead of IPs
• This is expected behavior

---

🏁 Summary

NextDNS adds "exit 0" → breaks dnsmasq.postconf

Fix:

Patch that exit → restore original logic

---

🤖 Credit

Solved with ChatGPT through debugging and testing.