dns and subdomain (not understand all)

gliu ryuu-gou at mail1.dnet.gr.jp
Sat Feb 2 02:03:11 UTC 2002

Thank you for your reply.But I am still confused.

> >1. How can not I ping nameserver at internet although i setup the
> >root.cache.Is it for the local ip address? Can I do it if I use the true
> >internet address(
> Maybe there's a firewall blocking your Linux box's DNS queries.

1 .I have used "dig" to test my dns server (bind 8.2.5).If I run it (just dig and no options) on the clients which use my test server as its domain server,it shows nothing including the RRs.But when it use the nameserver for go.nu, at least it showed the contents of file root.cache.Why? 

my result like this
% dig 
;; Total query time: 6 msec
;; FROM: fairy.deutsch to SERVER: default --
;; WHEN: Wed Dec  6 12:49:21 2001
;; MSG SIZE  sent: 25  rcvd: 125

But I use ping and nslookup tools ,I found they knew the name and ip address correctly.

Is it true that dig will show all the data stored in the dns server including the RRs and root.cache?

2. How can I know my dns queries are blocked by the firewall? I can not use telnet ip 53 for it use tcp protocol.

> >2. Do I have to use the localhost and 0.0.127.in-addr.arpa as two zones.
> >System knows localhost and each others in default.
> Yes.  One is the forward zone, the other is the reverse.

But who care the data,for all the clients want are the realname and internet/intranet ip.They are not interest in  localhost and of the dns server.

> >3. As using "master" type ,how can the dns server  refresh its database
> >by the time ( 
> >    1997022700 ; Serial 
> >    28800 ; Refresh 
> >    14400 ; Retry 
> >    3600000 ; Expire 
> >    86400 ; Minimum )

> Master servers don't refresh automatically, you have to use "rndc reload
> s.go.nu".  The refresh time is only used by slave servers.

So you means all of the time setting except 86400(Minimum) are for telling the slave how to refresh  their data.So if I only have a master dns server, I can using any numbers like
  1980227000 ; Serial <-changed
  1 ; Refresh <-changed
  1 ; Retry <-changed
  1 ; Expire <-changed
  86400 ; Minimum )

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