diff --git a/media/mtransport/test/webrtcproxychannel_unittest.cpp b/media/mtransport/test/webrtcproxychannel_unittest.cpp
index 1f664d8cd51a..acae17fd0a3b 100644
--- a/media/mtransport/test/webrtcproxychannel_unittest.cpp
+++ b/media/mtransport/test/webrtcproxychannel_unittest.cpp
@@ -182,6 +182,10 @@ class FakeSocketTransportProvider : public nsISocketTransport {
     MOZ_ASSERT(false);
     return NS_OK;
   }
+  NS_IMETHOD ResolvedByTRR(bool *aResolvedByTRR) override {
+    MOZ_ASSERT(false);
+    return NS_OK;
+  }
 
   // nsITransport
   NS_IMETHOD OpenInputStream(uint32_t aFlags, uint32_t aSegmentSize,
diff --git a/netwerk/base/nsISocketTransport.idl b/netwerk/base/nsISocketTransport.idl
index c59ebe7a9104..ad9a58134128 100644
--- a/netwerk/base/nsISocketTransport.idl
+++ b/netwerk/base/nsISocketTransport.idl
@@ -314,4 +314,9 @@ interface nsISocketTransport : nsITransport
      * The value is set after PR_Connect is called.
      */
    readonly attribute boolean esniUsed;
+
+   /**
+     * IP address resolved using TRR.
+     */
+    bool resolvedByTRR();
 };
diff --git a/netwerk/base/nsSocketTransport2.cpp b/netwerk/base/nsSocketTransport2.cpp
index 6b8808b6e0f1..fb0c7281fe96 100644
--- a/netwerk/base/nsSocketTransport2.cpp
+++ b/netwerk/base/nsSocketTransport2.cpp
@@ -708,6 +708,7 @@ nsSocketTransport::nsSocketTransport()
       mInputClosed(true),
       mOutputClosed(true),
       mResolving(false),
+      mResolvedByTRR(false),
       mDNSLookupStatus(NS_OK),
       mDNSARequestFinished(0),
       mEsniQueried(false),
@@ -1803,6 +1804,7 @@ bool nsSocketTransport::RecoverFromError() {
     // try next ip address only if past the resolver stage...
     if (mState == STATE_CONNECTING && mDNSRecord) {
       nsresult rv = mDNSRecord->GetNextAddr(SocketPort(), &mNetAddr);
+      mDNSRecord->IsTRR(&mResolvedByTRR);
       if (NS_SUCCEEDED(rv)) {
         SOCKET_LOG(("  trying again with next ip address\n"));
         tryAgain = true;
@@ -2096,6 +2098,7 @@ void nsSocketTransport::OnSocketEvent(uint32_t type, nsresult status,
       mDNSTxtRequest = nullptr;
       if (mDNSRecord) {
         mDNSRecord->GetNextAddr(SocketPort(), &mNetAddr);
+        mDNSRecord->IsTRR(&mResolvedByTRR);
       }
       // status contains DNS lookup status
       if (NS_FAILED(status)) {
@@ -3523,5 +3526,11 @@ nsSocketTransport::GetEsniUsed(bool *aEsniUsed) {
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsSocketTransport::ResolvedByTRR(bool *aResolvedByTRR) {
+  *aResolvedByTRR = mResolvedByTRR;
+  return NS_OK;
+}
+
 }  // namespace net
 }  // namespace mozilla
diff --git a/netwerk/base/nsSocketTransport2.h b/netwerk/base/nsSocketTransport2.h
index 904a241557c0..ee7d86e82f6d 100644
--- a/netwerk/base/nsSocketTransport2.h
+++ b/netwerk/base/nsSocketTransport2.h
@@ -328,6 +328,7 @@ class nsSocketTransport final : public nsASocketHandler,
 
   nsCOMPtr<nsICancelable> mDNSRequest;
   nsCOMPtr<nsIDNSRecord> mDNSRecord;
+  bool mResolvedByTRR;
 
   nsresult mDNSLookupStatus;
   PRIntervalTime mDNSARequestFinished;
diff --git a/netwerk/dns/nsDNSService2.cpp b/netwerk/dns/nsDNSService2.cpp
index ed20e02016b8..4d3cdf3346db 100644
--- a/netwerk/dns/nsDNSService2.cpp
+++ b/netwerk/dns/nsDNSService2.cpp
@@ -118,6 +118,7 @@ nsDNSRecord::IsTRR(bool *retval) {
   }
   return NS_OK;
 }
+
 NS_IMETHODIMP
 nsDNSRecord::GetNextAddr(uint16_t port, NetAddr *addr) {
   if (mDone) {
diff --git a/netwerk/protocol/http/TunnelUtils.cpp b/netwerk/protocol/http/TunnelUtils.cpp
index 834e2866cbb0..231a5452c7ef 100644
--- a/netwerk/protocol/http/TunnelUtils.cpp
+++ b/netwerk/protocol/http/TunnelUtils.cpp
@@ -1827,6 +1827,14 @@ SocketTransportShim::GetEsniUsed(bool *aEsniUsed) {
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
+NS_IMETHODIMP
+SocketTransportShim::ResolvedByTRR(bool *aResolvedByTRR) {
+  if (mIsWebsocket) {
+    LOG3(("WARNING: SocketTransportShim::IsTRR %p", this));
+  }
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
 #define FWD_TS_PTR(fx, ts) \
   NS_IMETHODIMP            \
   SocketTransportShim::fx(ts *arg) { return mWrapped->fx(arg); }
diff --git a/netwerk/protocol/http/nsHttpChannel.cpp b/netwerk/protocol/http/nsHttpChannel.cpp
index 44c6c7d1cc2d..87ff4a937af1 100644
--- a/netwerk/protocol/http/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/nsHttpChannel.cpp
@@ -8429,11 +8429,15 @@ nsHttpChannel::OnTransportStatus(nsITransport *trans, nsresult status,
       status == NS_NET_STATUS_WAITING_FOR) {
     if (mTransaction) {
       mTransaction->GetNetworkAddresses(mSelfAddr, mPeerAddr);
+      mResolvedByTRR = mTransaction->ResolvedByTRR();
     } else {
       nsCOMPtr<nsISocketTransport> socketTransport = do_QueryInterface(trans);
       if (socketTransport) {
         socketTransport->GetSelfAddr(&mSelfAddr);
         socketTransport->GetPeerAddr(&mPeerAddr);
+        bool isTrr = false;
+        socketTransport->ResolvedByTRR(&isTrr);
+        mResolvedByTRR = isTrr;
       }
     }
   }
diff --git a/netwerk/protocol/http/nsHttpChannel.h b/netwerk/protocol/http/nsHttpChannel.h
index 5cc784f07d2f..64cf05e6e372 100644
--- a/netwerk/protocol/http/nsHttpChannel.h
+++ b/netwerk/protocol/http/nsHttpChannel.h
@@ -706,6 +706,10 @@ class nsHttpChannel final : public HttpBaseChannel,
   // Used to suspend any newly created pumps in mCallOnResume handler.
   uint32_t mAsyncResumePending : 1;
 
+  // If the request was performed to a TRR resolved IP address.
+  // Will be false if loaded from the cache.
+  uint32_t mResolvedByTRR : 1;
+
   nsTArray<nsContinueRedirectionFunc> mRedirectFuncStack;
 
   // Needed for accurate DNS timing
diff --git a/netwerk/protocol/http/nsHttpTransaction.cpp b/netwerk/protocol/http/nsHttpTransaction.cpp
index 99516732455d..de571e29bf8c 100644
--- a/netwerk/protocol/http/nsHttpTransaction.cpp
+++ b/netwerk/protocol/http/nsHttpTransaction.cpp
@@ -143,6 +143,7 @@ nsHttpTransaction::nsHttpTransaction()
       mPassedRatePacing(false),
       mSynchronousRatePaceRequest(false),
       mClassOfService(0),
+      mResolvedByTRR(false),
       m0RTTInProgress(false),
       mDoNotTryEarlyData(false),
       mEarlyDataDisposition(EARLY_NONE),
@@ -591,6 +592,7 @@ void nsHttpTransaction::OnTransportStatus(nsITransport *transport,
       MutexAutoLock lock(mLock);
       socketTransport->GetSelfAddr(&mSelfAddr);
       socketTransport->GetPeerAddr(&mPeerAddr);
+      socketTransport->ResolvedByTRR(&mResolvedByTRR);
     }
   }
 
diff --git a/netwerk/protocol/http/nsHttpTransaction.h b/netwerk/protocol/http/nsHttpTransaction.h
index aa70956904aa..f06d2cc0dcc2 100644
--- a/netwerk/protocol/http/nsHttpTransaction.h
+++ b/netwerk/protocol/http/nsHttpTransaction.h
@@ -464,10 +464,12 @@ class nsHttpTransaction final : public nsAHttpTransaction,
 
  public:
   void GetNetworkAddresses(NetAddr &self, NetAddr &peer);
+  bool ResolvedByTRR() { return mResolvedByTRR; }
 
  private:
   NetAddr mSelfAddr;
   NetAddr mPeerAddr;
+  bool mResolvedByTRR;
 
   bool m0RTTInProgress;
   bool mDoNotTryEarlyData;