Enough for what job???? I'm a systems admin and have about 12 years experience on the job. I used to have a CCNA and I felt that it provided value as it said that I knew some of the basics about networking and helped me with subnetting, routing and vlan usage. However, I also have certs from Microsoft and Red Hat to round out some of my systems credentials as well. Their is a lot from a network perspective to be gained studying for the CCNA, it's a solid exam and does require a fair amount of effort to maintain.
For the places that I worked, the majority of the network engineers had CCNP's.