An interesting question I was once asked was what did my home network look like. I answered that it was pretty simple, a basic Linksys broadband router and a couple of Windows desktops. At the end of the interview, he told me he'd like to have heard I was doing more interesting things at home as he felt your home network is a great place to test out firewall setups, build lab scenarios, etc. I told him I agreed with that and could see his point, but my current position affords me plenty of time to work on those things and at home, I just want things to work.
In the same interview, he told me he was disappointed I wasnt more interested in the open-source VoIP systems being deployed.
The position I was interviewing for is still unfilled, and if offered I will not take it.
In a much more professional interview, I had my brain cooked by the technical director/CCIE. Be as up to speed on the different technologies you think the position might be using as you should be in the junior/senior level your applying for. If you are looking at a position in a campus network, read up on best practices for high-availability campus design for example. All networks are different and will operate with different budgets. A strong technical interview may consist of asking you what you know and can explain about each technology they use.
Be honest about the things you know and to how much depth you know them, what your familiar with and what things you have never even heard of. Show your desire and willingness to learn and you'll get the right position for yourself one day!