diff --git a/test/support_test.sh b/test/support_test.sh
index 107f66c..c92ed93 100644
--- a/test/support_test.sh
+++ b/test/support_test.sh
@@ -30,9 +30,6 @@ test_start "$0|support test: does 'bpftune -S' show support level?"
 
 ARCH=$(uname -m)
 
-MAJ_KVER=$(uname -r | awk -F '.' '{print $1}')
-MIN_KVER=$(uname -r | awk -F '.' '{print $2}')
-
 expected="bpftune is not supported"
 expected_netns="does not support per-netns policy"
 
diff --git a/test/test_lib.sh b/test/test_lib.sh
index 6e86585..e7f6aac 100644
--- a/test/test_lib.sh
+++ b/test/test_lib.sh
@@ -162,6 +162,9 @@ export PYTHONCMD="python3 -B"
 
 export EXITCODE=1
 
+export MAJ_KVER=$(uname -r | awk -F '.' '{print $1}')
+export MIN_KVER=$(uname -r | awk -F '.' '{print $2}')
+
 bold()
 {
 	echo "${B}$1${N}"
diff --git a/test/udp_mem_exhaust_test.sh b/test/udp_mem_exhaust_test.sh
index 1c39d77..503d528 100644
--- a/test/udp_mem_exhaust_test.sh
+++ b/test/udp_mem_exhaust_test.sh
@@ -29,7 +29,15 @@ SLEEPTIME=5
 TIMEOUT=30
 MAX_CONN=10
 
-for FAMILY in ipv4 ipv6 ; do
+# udp_fail_queue_rcv_skb tracepoint IPv6 support only on 6.4+ kernels.
+FAMILIES="ipv4"
+if [[ $MAJ_KVER -ge 6 ]]; then
+	if [[ $MIN_KVER -ge 4 ]]; then
+		FAMILIES="$FAMILIES ipv6"
+	fi
+fi
+
+for FAMILY in $FAMILIES ; do
 
    case $FAMILY in
    ipv4)
@@ -44,8 +52,6 @@ for FAMILY in ipv4 ipv6 ; do
 
    rmem_default_orig=$(sysctl -n net.core.rmem_default)
    sysctl -w net.core.rmem_default=8192
-   #rmem_max_orig=$(sysctl -n net.core.rmem_max)
-   #sysctl -w net.core.rmem_max=8192
    mem_orig=($(sysctl -n net.ipv4.udp_mem))
 
    mem_test=($(echo 10 20 20))
@@ -73,9 +79,7 @@ for FAMILY in ipv4 ipv6 ; do
    done
 
    mem_post=($(sysctl -n net.ipv4.udp_mem))
-   rmem_max_post=$(sysctl -n net.core.rmem_max)
    sysctl -w net.ipv4.udp_mem="${mem_orig[0]} ${mem_orig[1]} ${mem_orig[2]}"
-   #sysctl -w net.core.rmem_max=${rmem_max_orig}
    sysctl -w net.core.rmem_default=${rmem_default_orig}
    echo "mem before ${mem_test[0]} ${mem_test[1]} ${mem_test[2]}"
    echo "mem after ${mem_post[0]} ${mem_post[1]} ${mem_post[2]}"
diff --git a/test/udp_rmem_legacy_test.sh b/test/udp_rmem_legacy_test.sh
index fed95f4..c5e374a 100644
--- a/test/udp_rmem_legacy_test.sh
+++ b/test/udp_rmem_legacy_test.sh
@@ -29,7 +29,15 @@ SLEEPTIME=5
 TIMEOUT=30
 MAX_CONN=1
 
-for FAMILY in ipv4 ipv6 ; do
+# udp_fail_queue_rcv_skb tracepoint IPv6 support only on 6.4+ kernels.
+FAMILIES="ipv4"
+if [[ $MAJ_KVER -ge 6 ]]; then
+	if [[ $MIN_KVER -ge 4 ]]; then
+		FAMILIES="$FAMILIES ipv6"
+	fi
+fi
+
+for FAMILY in $FAMILIES ; do
  for BW in 500m 1000m 5000m 10000m ; do
    case $FAMILY in
    ipv4)
diff --git a/test/udp_rmem_locked_test.sh b/test/udp_rmem_locked_test.sh
index 8ec578f..24b375e 100644
--- a/test/udp_rmem_locked_test.sh
+++ b/test/udp_rmem_locked_test.sh
@@ -29,7 +29,15 @@ SLEEPTIME=5
 TIMEOUT=30
 MAX_CONN=1
 
-for FAMILY in ipv4 ipv6 ; do
+# udp_fail_queue_rcv_skb tracepoint IPv6 support only on 6.4+ kernels.
+FAMILIES="ipv4"
+if [[ $MAJ_KVER -ge 6 ]]; then
+	if [[ $MIN_KVER -ge 4 ]]; then
+		FAMILIES="$FAMILIES ipv6"
+	fi
+fi
+
+for FAMILY in $FAMILIES ; do
  for BW in 500m ; do
    case $FAMILY in
    ipv4)
diff --git a/test/udp_rmem_test.sh b/test/udp_rmem_test.sh
index 57dc816..ea21078 100644
--- a/test/udp_rmem_test.sh
+++ b/test/udp_rmem_test.sh
@@ -29,7 +29,15 @@ SLEEPTIME=5
 TIMEOUT=30
 MAX_CONN=1
 
-for FAMILY in ipv4 ipv6 ; do
+# udp_fail_queue_rcv_skb tracepoint IPv6 support only on 6.4+ kernels.
+FAMILIES="ipv4"
+if [[ $MAJ_KVER -ge 6 ]]; then
+	if [[ $MIN_KVER -ge 4 ]]; then
+		FAMILIES="$FAMILIES ipv6"
+	fi
+fi
+
+for FAMILY in $FAMILIES ; do
  for BW in 500m 1000m 5000m 10000m ; do
    case $FAMILY in
    ipv4)