Hello
I want keywords in the router I block Is it possible? For example, the word " sex "
you can block keyword in webpage address if you use transparent proxy, but not keywords in webpages.
Full-blown content filtering based on page content is very extensive task, and prone to failure.
Want some examples? Google for
- Scunthorpe
- Craig Cockburn hotmail
- Dr. Herman I. Libshitz verizon
- Sussex county
- analytic signature mail problem
- nagiosexchange.org"
(and that is list can be filled further and further, let’s just look at https://en.wikipedia.org/wiki/Scunthorpe_problem).
Do you still wanna block something by keywrods in content? 
Better go with some sort of domains list published in many places online, or just configure OpenDNS with parental control option.
Edit:
Well done guys, you just proven that filtering by keywords is a terrible idea - “Dr. Herman I. Libs-h-i-tz” is displayed as “Dr. Herman I. Lib****it**z”.
And anyway. Sex is normal English word that means gender. You can find it in official documents like ID cards or passports. Do you still want to filter the traffic according it’s content? Do you know that reading transferred messages is criminal act in many countries?
That was fun to read. We had a former administrator of a spam firewall who was guilty of committing those kinds of mistakes, too. I think we had a customer whose name was cockburn and one day he called up angry because we were ignoring his emails to customer support… whoops.