Two servers, two NS ?

[Eminos]

Alright, Now I should try this How To.

Say me what is the [DNS.FROM.ISP] variable in the how to, and do I have to have that?
It says "It should include a nameserver from your isp as forwarder " .. why is that? Can't I just use my own two DNS' ? Shout I replace ISP DNS with my own NS2 ?

And also, this stuff:
"You need a key for secure zonetransfers on both nameservers. You can create a key with: (its in the <bla>.private file, only needed once and only on your NS1)
dnssec-keygen -a hmac-md5 -b 512 -n host [YOUR.NS1.FQDN]
"
Once it says on both NS' and then it says only needed on NS1 ?? Can someone just explain this, and point me in the right direction ?

Thanks.

/E