How to have 100% secure network?

Securing the Networking is a compromise between how can you protecting Network to Maximum without adding more complexity to it.

So Securing the Network100% is not applicable.

You cann't have a100 % network security but you can apply various of techniques such as rings of defense to provide more security

I do not believe such a thing as 100% security exists in this world for anything

Their is nothing called100% secured network.

100  secure network is impossible to achieve, even though your perimeter devices are well configured, you application codes don't have any flaws or you maintain excellent security policy. There are some instances when you run into some type of unstructured attacks, where employees are the weakest link, when they do harm to the network unintentionally. New threats that have not been addressed pose a risk at you network because your devices will not protect you against them. The best thing you can do is to continually assess the risk of your network ,find solutions and then monitor to see if the controls you established are working or not, and the cycle must repeat over and over. 

you  cannot have100% secure network

Yes no one can built100% secure network, but we can built a safe and secure network with applying accurately protocols, with security configuration on firewall, properly configuration router and switches. 

NO Network can be  100% secure. no one can claim also..

but we can secure our network by applying right policy's on router switch and firewall..follow the defence in depth model....

I think there's no way to have100% secured network, vulnerabilities and attacks are always being updated and developed faster than defense technologies. The best thing you can do is to minimize the danger of being hacked.

I think you will never have100% secure network, but you can have as close as99.99% if you carefully applied security protocols.

there is no such thing as 100 % secure network every digitial system has its own vulnerability , but a consistent update, under control network , well designed network infrastructure , security expert and always being up-to-date with the latest security threats and deffenses are a must to maintain the system. On the other hand penetration testing will definitely  help in recognizing the weak spots in the system in order to mitigate them as well as a network forensicator will analyse the DNA of the system to keep track of every action taken.  SECURITY AWERNESS IS A MUST TO BE DONE ATT ALL TIME IN EVERY COMPANY