after i've tried to understand how syslog is working in ubuntu i found out that the package that exist is sysklogd (syslogd & klogd combination).
what I want to do is to get my router messages (which i've succeed in) but to a separate file. I saw that it is possible through rsyslog with ruleset.
how is it possible to do it by sysklogd?
I don't believe the functionality is available. Looking at my 12.04 virtual servers it looks like rsyslogd has replaced sysklogd as the default logger. I replaced it earlier on my server because I wanted the additional filtering available in rsyslogd.
Standard syslog filtering is done on facility and priority. Neither of these is host specific. If it is possible to specify the facility your router logs as, you could use an unused
local
facility to fake the separation you are looking for.