Ping domain name vs nslookup IP
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From: Chris Cox on 23 Sep 2009 00:10 SL Da wrote: > 1. When I ping 'bayregatta.com' I see 209.160.33.87 > > 2. When I try 'nslookup 209.160.33.87', I get 'non-existent domain'. > > I am a bit confused. Can someone explain ? 1. Assuming the ping looked up bayregatta.com via DNS, that's a DNS A record lookup. 2. Since that is going to use the defined DNS, it's trying to find the PTR record associated by the IP. Specifically it is trying to lookup 87.33.160.209.in-addr.arpa. But apparently there is no zone for the PTR record, thus the message.
From: Wanna-Be Sys Admin on 23 Sep 2009 03:39 SL Da wrote: > I don't have much knowledge in this area. > > When I create a domain on a web server, there is no problem. I suppose > all entries are done automaticaly by the ISP's software. How do you mean? What is the issue you have? > But then suddenly there are problems (someone else's domain). First > the domain cannot be reached, now the reverse DNS does not work. I > think someone has tempered the DNS record, or removed the domain > account form the server (I guess). What do you mean someone else's domain and there being a problem? Which domain can't be reached? BTW, a domain not being responsive has nothing to do with the reverse DNS, so I assume you got a different error when running nsloopkup? Does it work at all? Perhaps there is an issue when one or the other name servers don't respond or something? Exactly what is the issue you're having? -- Not really a wanna-be, but I don't know everything.
From: SL Da on 23 Sep 2009 06:38 I maintained some web pages for a company a little while ago. Recently someone called me up, saying they cannot accessed its control panel. I understand that an IT guy has left the company not long ago, with a little grudge may be. I discovered I cannot ping the site (server failed); looked like a DNS error. It was restored a week later (not by me), but then the reverse DNS does not work. > What do you mean someone else's domain and there being a problem? Which > domain can't be reached? BTW, a domain not being responsive has > nothing to do with the reverse DNS, so I assume you got a different > error when running nsloopkup? Does it work at all? Perhaps there is an > issue when one or the other name servers don't respond or something? > Exactly what is the issue you're having? > > -- > Not really a wanna-be, but I don't know everything.
From: N. Bazan on 4 Oct 2009 04:46 On Sep 23, 3:31 am, SL Da <sb5...(a)yahoo.com> wrote: > 1. When I ping 'bayregatta.com' I see 209.160.33.87 > > 2. When I try 'nslookup 209.160.33.87', I get 'non-existent domain'. > > I am a bit confused. Can someone explain ? > > Thanks. When you ping bayregatta.com your get an A record back. A record contains 209.160.33.87 When you do nslookup 209.160.33.87 you perform something like reverse lookup for domain 209.160.33.87. There are no such domain and there are no ptr record for this ip. PTR records looks like this 209-160-33-87.your-isp.com and commonly maintained by isp`s. You do not need any ptr records for the website. But you have mail.bayregatta.com at same ip without ptr records. You must have one ptr for your mail server, otherwise your mail server ip can be blacklisted. Try to use some swiches such as nslookup -type=ptr(ns,soa,mx) 209.160.33.87. You can also find your full DNS report at http://www.magic-net.nl/dns-lookup.php or check your PTR direct http://www.magic-net.nl/dns-and-ip-tools.php?ptr=209.160.33.87&do=Find
From: N. Bazan on 4 Oct 2009 04:58
On Sep 23, 12:38 pm, SL Da <sb5...(a)yahoo.com> wrote: > I maintained some web pages for a company a little while ago. > > Recently someone called me up, saying they cannot accessed its control > panel. I understand that an IT guy has left the company not long ago, > with a little grudge may be. > > I discovered I cannot ping the site (server failed); looked like a DNS > error. It was restored a week later (not by me), but then the reverse > DNS does not work. > > > What do you mean someone else's domain and there being a problem? Which > > domain can't be reached? BTW, a domain not being responsive has > > nothing to do with the reverse DNS, so I assume you got a different > > error when running nsloopkup? Does it work at all? Perhaps there is an > > issue when one or the other name servers don't respond or something? > > Exactly what is the issue you're having? > > > -- > > Not really a wanna-be, but I don't know everything. Ping uses ICMP protocol that can be blocked by your firewall. ICMP is not necessary for the web-site. But you must have A record for your website that points to your ip, and one A record for your cpanel.website.com that points to same or different ip. Your web server must accept headers www.website.com and cpanel.website.com. |