<human>: Hi there,

working in a big trading company in the IT-department for about 3 years. It was real fun in the beginning because I've learned a lot (got some trainings, some travelling,...). 
But it is also a lot of 1st and 2nd level support which I think isn't the thing you have to study for (I have a diploma). Not because support is easy, but talking to people without having any idea of IT and what our department is doing is not my job.

Anyway, after a certain time I got bored and talked to my manger, that I want to work on more projects, get more money and stuff. After that, work was better for several month and I was quite comfortable with my job.

Some weeks ago there was an internal job offer as team-manager so my co-worker (team-coordinator) applied to it but didn't get the job (cause of reason i don't know exactly). So after that I asked him if it's ok for him if I would also apply to this job and if he would have any problems with it (he's older than me and has more work experience).
He said it would be OK and so I applied to the job too. My manager really appreciated my decision and said that he thinks this job would fit my skills blah blah - this was before my holidays.

Coming back to work my manager told me that there is an external applicant with good experience in the job and so on.
Long story short: the external applicant got the job and my manager did not even try to explain me why she got the job instead of me.

And here is the thing: I have really great colleagues and a lot of departments only want to work with me, because I really want to make a good job and keep business running, whereat my team-member is sometimes a kind of ney-sayer.

My question is if I should talk to my manager again and ask him if he sees any opportunity / future trend for or should I seek for another job without saying anything and just quit. The latter would be very bad for the company because only two persons (one is me) are able to work with the tool we need for external and internal data interchange (which is crucial for doing business at all).

Summarize the given text in a few sentences.
<bot>: boring work after 1 year, talked to manager,  some good projects, applied for  internal job offer,  job given to external applicant w/out talking to me,  talk to manager again or quit.