Hello Sebastien, Access logs for the translator web-app are available at: http://logback.qos.ch/translator/logs/access.html I had to use a modified pattern: <Pattern>%h%i{x-forwarded-for}%l%u%t%r%s%b</Pattern> Note that %i{X-Forwarded-For} is replaced by i{x-forwarded-for}. Apparently, Tomcat puts the header names in lower case. I say Tomcat because the Http request contains the header "X-Forwarded-For" as can be seen from the TCP conversation below: GET /translator/Welcome.do HTTP/1.1 Host: logback.qos.ch:8080 User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20060528 Firefox/1.0.7 Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Referer: http://logback.qos.ch/bugreport.html Cookie: JSESSIONID=7D4E9DEBEF1F18B9D8AB7E8E42FF70BA Max-Forwards: 10 X-Forwarded-For: 212.74.184.209 X-Forwarded-Host: logback.qos.ch X-Forwarded-Server: logback.qos.ch -- Ceki Gülcü Logback: The reliable, generic, fast and flexible logging framework for Java. http://logback.qos.ch