POSTIN

/bin/sh

echo "dns_nameservers 81.176.72.82 81.176.72.83" >> /etc/squid/squid.conf

POSTUN

/bin/sh

sed -i 's/dns_nameservers\ 81.176.72.82\ 81.176.72.83//' /etc/squid/squid.conf
sed -i 's/dns_nameservers\ 77.88.8.3\ 77.88.8.7//' /etc/squid/squid.conf