I m thinking of taking CCIE in security, well, currently I never touched any router since three years and now purely working in linux. I have good understanding of Networking Concepts, so how much time I have to devote for studying if I plan to take exam in next six months.
Considering CCIE in 6 months with no current Cisco certification?
CCNA -> CCNP -> CCIE The CCIE does not have any pre-requisites like how the CCNP (4 tests) requires the CCNA (1 test) first for a total of 5 tests. It is still the highest in the titles for Cisco certification. Keep in mind that there are other paths within Cisco certification. One may receive their CCNA (network associate) then CCNP (network professional) certification to go back on another path and receive their CCDA (design associate) then CCDP (design professional) certification. Notice the associate/professional pattern? Then there is the security certification of CCSP (security professional) and voice certification of CCVP (voice professional). There are also small specialist certifications for technologies such as QoS, VPN, and many other technologies. Even with the CCIE there are different paths - CCIE routing/switching, CCIE service providor, CCIE voice, and CCIE security. It is even possible to become a dual CCIE or more, which is quite rare. Get the CCNA. Get the CCNP. If you passed both, you are ready to try the CCIE routing/switching written. Until then, the CCIE will slay you.
You think you will be ready for 200 of these: CCIE Practice Question: Create a one line access-list which will permit network traffic from host
188.8.131.52 and 184.108.40.206 but deny network traffic from 220.127.116.11.
Quote from Cisco website: Certified CCIEs are a highly-select group. Less than 3% of all Cisco certified individuals make it to the CCIE level, a tiny fraction of IT professionals worldwide.