secondary server install

[Bill Friedman]

Sorry if my questions seem particularly ignorant.  I've attempted to 
answer my questions answered via research, but, there seems to be a lot 
of implicit understanding of dns on the net, and some of the fundamental 
concepts still probably allude me.

I should mention that my motive for setting this up is that we plan to 
do some hw maintenance on the current master server onsite.  Based on 
named.conf allow-lists looks like there are 3 isps hosted nameservers 
serving as secondary servers.  At any rate I figure better have a backup 
in case the maintenance takes longer thant 12 hour refresh time for the 
isp hosted nameservers.  Does setting up a slave server onsite make 
sense in this case?  My understanding is that the only distinction is 
that changes are made on the master which then updates the slave. 
 Otherwise, I'm not sure what the difference in functionality is.

Anyway, here are some additional questions.

1)if allow-transfers is where you set permissions for other name-servers 
to request zone info, then if I don't have the isp servers listed 
somewhere in named.conf allow-transfers list, how will they be able to 
get zone info from the slave if the master goes down?

2)I need to add an ns record for the slave in the master's zone files, 
correct?
Seems like I would need to notify the isp of the slave nameserver as well

3)Is the SOA defined as the master server on the slave machine as well? 
 I believe that's what I've read, although, I guess that means that 
queries handled by the slave if the master goes away are 
non-authoritative, and I'm not sure what the implications of that are.

thanks


Barry Margolin wrote:

>
>No, you should put the master server's IP in the "masters" clause.  You don't
>need "allow-transfer" on the slave, because the ISP's servers will continue
>transfering from the master, not the slave.
>
>  
>
>>zone "mydomain.com" in {
>>       type slave;
>>       file "db.mydomain";
>>       notify no;
>>       allow-transfer {
>>               192.168.0.5;
>>               206.228.179.10;
>>               144.228.254.10;
>>               144.228.255.10;
>>       };
>>};
>>    
>>
>
>zone "mydomain.com" in {
>  type slave;
>  file "db.mydomain";
>  notify no;
>  masters { 192.168.0.5; };
>};
>
>  
>