diff --git a/dns.sh b/dns.sh
new file mode 100644
index 0000000..e1e102a
--- /dev/null
+++ b/dns.sh
@@ -0,0 +1,23 @@
+##################################
+#
+# DNS Helper
+#
+##################################
+
+function zju_test_and_set_up_dns() {
+    until [ -z "$1" ]
+    do
+        dig baidu.com @$1 +time=1 > /dev/null && echo "$1 ... ok" && echo "nameserver $1" > /etc/resolv.conf && break
+        echo "$1 ... fail"
+        shift
+    done
+}
+
+# 浙大的DNS不是很稳定，这里列了备用方案
+# 官方 > 10.12.10.12 > Senorsen DNS > RQ Lab > ALI YUN
+zju_test_and_set_up_dns \
+    10.10.0.21 10.10.0.22 10.10.0.23 \
+    10.12.10.12 \
+    10.76.8.111 \
+    10.202.68.222 \
+    223.5.5.5 223.6.6.6