How much experience before your resume doesn't get instantly disregarded?

I've been working as a network tech for a year and a half now. It's my first IT job, but I feel like I'm getting good experience for it being my first. I'm working with Cisco routers, and quite a few networking protocols/technologies.

For the past few months, I've been casually looking and applying for network administration/(junior) engineering positions (I want to move up into that role), but with very little luck. I always rather get the standard automatic rejection email or I'm told I don't have enough experience yet. How many years of experience will I need before I'm taken seriously? Or do I just need to fluff up my resume to make it sound like I have more than a year and a half of experience?

Also, I know certs go a long way, so I'm currently studying for my CCNA, but it's quite expensive for me and my work wouldn't cover it or give me any additional comp for having it so I'm kind of stuck between getting it now or waiting.

Any advice? Thanks!