diff --git a/custom.yaml b/custom.yaml
index c056c3bf1..6281ef7a5 100644
--- a/custom.yaml
+++ b/custom.yaml
@@ -1,3 +1,11 @@
+# Switch network to calico
 kube_network_plugin: "calico"
+# Kube-proxy should be iptables for calico
 kube_proxy_mode: "iptables"
+# Use non-tmpfs tmp dir
 local_release_dir: "/var/tmp/releases"
+# Upstream DNS servers with mirantis.net
+upstream_dns_servers:
+  - 8.8.8.8
+  - 8.8.4.4
+  - /mirantis.net/172.18.32.6