при компиляции freeswitch

checking for libldns >= 1.6.6... checking for ldns_str2rdf_a in -lldns... no
configure: error: You need to either install libldns-dev or disable mod_enum in modules.conf

Подключите EPEL repo

wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
wget http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
rpm -Uvh remi-release-6*.rpm epel-release-6*.rpm

установите ldns и ldns-devel

yum install  ldns ldns-devel -y