Within the Red Hat certification program, the RHCA is considered the most complete (and grueling) certification among the seven major Red Hat certifications. In fact, some equate the prestige of the RHCA to that of the Microsoft Certified Master and possibly the CCIE.
A plumbing fixture like a sink can not function properly without a sink vent. When a drain pipe drains it creates a negative pressure in the sink drain; the negative pressure will pull the water out of the p-trap of the sink that's draining and sewer gases can enter your home if a sink vent is not installed.
If you cannot connect the sink drain to the toilet drain within 6 feet of the toilet, install a separate vent on the toilet drain line closer to the toilet. The farther the sink connection from the toilet, the more likely you are to experience clogs. The sink will still need a separate vent pipe.