diff --git a/kubuntu/kubuntu_late_command.sh b/kubuntu/kubuntu_late_command.sh
index a80fa54..5b5112a 100644
--- a/kubuntu/kubuntu_late_command.sh
+++ b/kubuntu/kubuntu_late_command.sh
@@ -9,11 +9,11 @@
 export DEBIAN_FRONTEND=noninteractive
 DPKG_CFG_FRAGMENT=/etc/dpkg/dpkg.cfg.d/non-interactive
 
-# ChCh apt proxy benutzen
-
-echo 'Acquire::https::Proxy "http://172.23.92.240:3142";' > /etc/apt/apt.conf.d/01aptproxy
-echo 'Acquire::http::Proxy "http://172.23.92.240:3142";' >> /etc/apt/apt.conf.d/01aptproxy
-
+# ChCh apt proxy benutzen (bedingt = wenn da)
+if [ ping -n 1 apt-cache ]; then
+	echo 'Acquire::https::Proxy "http://apt-cache:3142";' > /etc/apt/apt.conf.d/01aptproxy
+	echo 'Acquire::http::Proxy "http://apt-cache:3142";' >> /etc/apt/apt.conf.d/01aptproxy
+fi
 
 # Linux distro
 script_distro='Kubuntu Linux 20.4.0'