To a large extent, it is up to you to keep up with the technologies. Read trade magazines, technology news on the web, continue to read books. Some companies offer training and education, but many do not. Those that do offer training, that can vary quality depending on the amount of many they can spend or are willing to spend.
You cannot rely on your company to introduce you to new ideas in technology. In fact, in many cases, it is among your responsibilies to educate your company in what options are available for that company to maintain operations, minimum security levels, current hw/sw platforms, etc... So you're going to have to make an effort to pay attention to what is happening around you and to what is happening in the industry.
This is really a two way street. You may come across something that you believe will provide a vlauable service to your organization. Your organization may come back and provide funding for you to receive specific training so that you can implement that service.
Although your question is specific to "networking", I'm addressing this to all IT professionals as it applies in all fields. The bottom line here is that you have to have a degree of initiative and discipline in order to be a valuable IT professional.