The problems are not yet solved but I can see that I'm on my way! I never point a local debian machine on Internet that is why I'm getting confuse, Another issue is the Cisco router that I can't have access! so I discovered problems when I try to implement somethings
I can now ping 41.134.19.90 and 41.134.19.91 from my LAN. It's like the above IPs are pointing on 41-134-19-90.dsl.mweb.co.za and 41-134-19-91.dsl.mweb.co.za but I request to my ISP to changed them to ns1.kom.co.za and ns2.kom.co.zaso that I can have my own DNS server