Command:
apt list --installed | grep snmp

Result:
libsnmp-base/xenial,xenial,now 5.7.3+dfsg-1ubuntu4 all [installed,automatic]
libsnmp30/xenial,now 5.7.3+dfsg-1ubuntu4 amd64 [installed,automatic]
php7.0-snmp/xenial-updates,now 7.0.18-0ubuntu0.16.04.1 amd64 [installed]