I passed the CCNA last year and I've seen this question asked a lot. So here's your answer. CCNA has little to do with Security and Security related beginner certifications like the Security+ and the CEH are better for Security related roles. But, to understand a lot of stuff in security you need a thorough understanding of networking concepts. You could just learn all of it for free on the internet, but certifications show a recruiter that you understand it and have been tested. Also, it looks really good on your resume. You will learn networking concepts that will help you when you start concentrating on Security. Topics like OSI layers and protocols, TCP/IP Model, TCP, UDP, IPv4, IPv6, ARP, DHCP, DNS, MAC, Encryption, SSH, Telnet, FTP, NAT, SNMP, Routing and Switching protocols(OSPF, RIP, BGP etc). You will also learn key concepts in network security and general security like WiFi security protocols, ARP and DHCP attacks, threats, vulnerabilities, port securit...
My journey to becoming a Security Professional