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Change default DNS resolvers and MTU to 1500 #36

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Merged
hawkff merged 3 commits into from
Jun 19, 2026
Merged

Change default DNS resolvers and MTU to 1500 #36

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fb6bad1
Change default DNS to Quad9 and MTU to 1500
hawkff Jun 19, 2026
03725eb
Use Quad9 IP endpoint for direct DNS default
hawkff Jun 19, 2026
a3eb787
Use Cloudflare IP endpoint for direct DNS default
hawkff Jun 19, 2026
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6 changes: 3 additions & 3 deletions app/src/main/java/io/nekohasekai/sagernet/database/DataStore.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -109,7 +109,7 @@ object DataStore : OnPreferenceDataStoreChangeListener {
var trafficSniffing by configurationStore.stringToInt(Key.TRAFFIC_SNIFFING) { 1 }
var resolveDestination by configurationStore.boolean(Key.RESOLVE_DESTINATION)

var mtu by configurationStore.stringToInt(Key.MTU) { 9000 }
var mtu by configurationStore.stringToInt(Key.MTU) { 1500 }

var bypassLan by configurationStore.boolean(Key.BYPASS_LAN)
var bypassLanInCore by configurationStore.boolean(Key.BYPASS_LAN_IN_CORE)
Expand All @@ -125,8 +125,8 @@ object DataStore : OnPreferenceDataStoreChangeListener {

var globalCustomConfig by configurationStore.string(Key.GLOBAL_CUSTOM_CONFIG) { "" }

var remoteDns by configurationStore.string(Key.REMOTE_DNS) { "https://dns.google/dns-query" }
var directDns by configurationStore.string(Key.DIRECT_DNS) { "https://223.5.5.5/dns-query" }
var remoteDns by configurationStore.string(Key.REMOTE_DNS) { "https://dns.quad9.net/dns-query" }
var directDns by configurationStore.string(Key.DIRECT_DNS) { "https://1.1.1.1/dns-query" }

@coderabbitai coderabbitai Bot Jun 19, 2026

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⚠️ Potential issue | 🟠 Major | ⚡ Quick win

Direct DNS default does not match the stated Quad9 objective.

directDns is set to Cloudflare (1.1.1.1), but the PR objective specifies Quad9 IP-based DoH (9.9.9.9) for DNSSEC + malicious-domain blocking defaults. Please align both code and XML to the intended provider.

Suggested fix 
--- a/app/src/main/java/io/nekohasekai/sagernet/database/DataStore.kt
+++ b/app/src/main/java/io/nekohasekai/sagernet/database/DataStore.kt
@@
-    var directDns by configurationStore.string(Key.DIRECT_DNS) { "https://1.1.1.1/dns-query" }
+    var directDns by configurationStore.string(Key.DIRECT_DNS) { "https://9.9.9.9/dns-query" }

--- a/app/src/main/res/xml/global_preferences.xml
+++ b/app/src/main/res/xml/global_preferences.xml
@@
-            app:defaultValue="https://1.1.1.1/dns-query"
+            app:defaultValue="https://9.9.9.9/dns-query"
🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@app/src/main/java/io/nekohasekai/sagernet/database/DataStore.kt` at line 129,
The default DNS provider in the directDns variable is set to Cloudflare
(1.1.1.1) instead of the intended Quad9 provider (9.9.9.9) for DNSSEC and
malicious-domain blocking. Change the hardcoded default value in the directDns
declaration from "https://1.1.1.1/dns-query" to "https://9.9.9.9/dns-query" to
align with the PR objective.

var enableDnsRouting by configurationStore.boolean(Key.ENABLE_DNS_ROUTING) { true }
var enableFakeDns by configurationStore.boolean(Key.ENABLE_FAKEDNS) { true }

Expand Down
6 changes: 3 additions & 3 deletions app/src/main/res/xml/global_preferences.xml
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Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,7 @@
app:title="@string/tun_implementation"
app:useSimpleSummaryProvider="true" />
<moe.matsuri.nb4a.ui.MTUPreference
app:defaultValue="9000"
app:defaultValue="1500"
app:entries="@array/mtu_select"
app:entryValues="@array/mtu_select"
app:icon="@drawable/baseline_public_24"
Expand Down Expand Up @@ -195,7 +195,7 @@

<PreferenceCategory app:title="@string/cag_dns">
<EditTextPreference
app:defaultValue="https://dns.google/dns-query"
app:defaultValue="https://dns.quad9.net/dns-query"
app:icon="@drawable/ic_action_dns"
app:key="remoteDns"
app:title="@string/remote_dns"
Expand All @@ -208,7 +208,7 @@
app:title="@string/domain_strategy_for_remote"
app:useSimpleSummaryProvider="true" />
<EditTextPreference
app:defaultValue="https://223.5.5.5/dns-query"
app:defaultValue="https://1.1.1.1/dns-query"
app:icon="@drawable/ic_action_dns"
app:key="directDns"
app:title="@string/direct_dns"
Expand Down
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