diff --git a/build.xml b/build.xml
index 4eb1f1f3c5..9dab8ac19b 100644
--- a/build.xml
+++ b/build.xml
@@ -413,7 +413,7 @@
           <dependency groupId="com.addthis.metrics" artifactId="reporter-config3" version="3.0.0" />
           <dependency groupId="org.mindrot" artifactId="jbcrypt" version="0.3m" />
           <dependency groupId="io.airlift" artifactId="airline" version="0.6" />
-          <dependency groupId="io.netty" artifactId="netty-all" version="4.0.36.Final" />
+          <dependency groupId="io.netty" artifactId="netty-all" version="4.0.37.Final" />
           <dependency groupId="com.google.code.findbugs" artifactId="jsr305" version="2.0.2" />
           <dependency groupId="com.clearspring.analytics" artifactId="stream" version="2.5.2" />
           <dependency groupId="com.datastax.cassandra" artifactId="cassandra-driver-core" version="3.0.1" classifier="shaded">
diff --git a/conf/cassandra-env.ps1 b/conf/cassandra-env.ps1
index 9373ba6b06..8c4311cfbf 100644
--- a/conf/cassandra-env.ps1
+++ b/conf/cassandra-env.ps1
@@ -350,6 +350,15 @@ Function SetCassandraEnvironment
     #$env:HEAP_NEWSIZE="800M"
     CalculateHeapSizes
 
+    # Direct memory used for native-protocol network I/O is no longer
+    # managed by the JVM. Instead, Netty allows three options to
+    # manage it via the system property io.netty.maxDirectMemory:
+    #     == 0  behavior as before, uses JVM to manage direct memory (slowest).
+    #     < 0   manages direct memory directly, max direct memory as -XX:MaxDirectMemorySize.
+    #     > 0   manages direct memory directly, max direct memory as specified.
+    #           Note, that appreviations like 2g or 500m are NOT accepted.
+    #$env:JVM_OPTS="$env:JVM_OPTS -Dio.netty.maxDirectMemory=2147483648"
+
     ParseJVMInfo
 
     # We only set -Xms and -Xmx if they were not defined on jvm.options file
diff --git a/conf/cassandra-env.sh b/conf/cassandra-env.sh
index 93434c9d60..6d5de213bd 100644
--- a/conf/cassandra-env.sh
+++ b/conf/cassandra-env.sh
@@ -167,6 +167,15 @@ USING_G1=$?
 # Set this to control the amount of arenas per-thread in glibc
 #export MALLOC_ARENA_MAX=4
 
+# Direct memory used for native-protocol network I/O is no longer
+# managed by the JVM. Instead, Netty allows three options to
+# manage it via the system property io.netty.maxDirectMemory:
+#     == 0  behavior as before, uses JVM to manage direct memory (slowest).
+#     < 0   manages direct memory directly, max direct memory as -XX:MaxDirectMemorySize.
+#     > 0   manages direct memory directly, max direct memory as specified.
+#           Note, that appreviations like 2g or 500m are NOT accepted.
+#export JVM_OPTS="$JVM_OPTS -Dio.netty.maxDirectMemory=2147483648"
+
 # only calculate the size if it's not set manually
 if [ "x$MAX_HEAP_SIZE" = "x" ] && [ "x$HEAP_NEWSIZE" = "x" -o $USING_G1 -eq 0 ]; then
     calculate_heap_sizes
diff --git a/lib/licenses/netty-all-4.0.36.Final.txt b/lib/licenses/netty-all-4.0.37.Final.txt
similarity index 100%
rename from lib/licenses/netty-all-4.0.36.Final.txt
rename to lib/licenses/netty-all-4.0.37.Final.txt
diff --git a/lib/netty-all-4.0.36.Final.jar b/lib/netty-all-4.0.37.Final.jar
similarity index 69%
rename from lib/netty-all-4.0.36.Final.jar
rename to lib/netty-all-4.0.37.Final.jar
index 5e278c4dbe..f0bcdac1b1 100644
Binary files a/lib/netty-all-4.0.36.Final.jar and b/lib/netty-all-4.0.37.Final.jar differ