subdomain URL not accessible through browser - asp.net

I am facing a strange issue.
My ISP has hosted a webservice inside a virtual directory which is placed under a subdomain. now from my system (or network) I cannot access that webservice. Every time I run fiddler, I see a DNS Lookup for "my_sub_domain.com" failed. No such host is known.
But If I run it through web-sniffer.com, it is returning as Status: HTTP/1.1 200 OK
I do not understand what is wrong, Have anyone faced something like this? Is there any problem with my network settings? Can you tell me how to fix this?
If you need any more information please let me know.

This sounds like a DNS issue. Your DNS server doesn't seem to have had the A record for the subdomain propagated to it yet, whereas the DNS server used by web-sniffer.com has had it propagated to it, and thus, can see that it's returning a valid record and IP address.
While waiting for it to propagate to your DNS provider, you could add an entry to your machine's host file with the correct IP address to allow you to continue work.

Related

Can I tell within application code, on what outermost port of my server the app is accessed?

I'm trying to open with the question that I really want answered. I want the URL at which outside users can access a particular part of my application.
In my server's setup, we're using Nginx as a reverse proxy, so my app is confugured to be at port 9000. But I can't point users at this, because they can't access that port. Users can access port 8080. But this is part of my system configuration and could (I think) change. Also it does change from development to staging to production. So, I would like to avoid hard-coding this if possible.
So then my question, can I somehow, dynamically, tell the "outermost" port that an incoming request is received at? Possibly through passing a header down from Nginx? I'm thinking of X-Forwarded-For, except I want to know what URL the client contacted to reach me (the server), not what IP address the client is contacting the server from. Is this possible?
$server_port variable holds the port the client connected to.

Unable to resolve CRM web application url with hostname from outside browsers

I have a deployment created with crm 2016 on-premise.
After installation. I am unable to use the webapplication URL from browsers outside the server.
If I use FQDN NAME-IT IS GETTING RESOLVING and able to access org. Eg:
http://testserver.testserverdom.com/Englishorg
If I use hostname url-it is not resolving and getting blank page. Eg:
http://testserver/EnglishOrg
Again if I add host entry in drivers/etc/hosts file in the outside machine like 10.10.10.10 testserver. Able to resolve and access URL.
I have added hostname(A) entry in DNS. I am still unable to resolve it with hostname.
Server have DHCP Assigned IP Address.
I believe you might be having the DNS issue on client - side (outside of you server) which cannot correctly resolve your testserver.
If you run cmd and there try nslookup testserver- you should see if this is resolved with the correct ip address (according you your hosts file change this should be 10.10.10.10). If this does not -- I believe the problem is in DNS query / response, please make sure your local DNS server is configured correctly and make sure your local DNS server is sending back the response to your client.

Server application key fails for specific server

To be clear, when I say "doesn't work", I meant that it returns a json object with a status of "REQUEST_DENIED". I always get a response.
I have a server key setup for the Geocode api, and I'm having an issue where it doesn't work with only one server. I've been using it locally (whitelisted my ip) without issue, and tested it with cURL on a Digital Ocean vps without issue.
On a WP Engine server, however, I cannot get it working. I've added the IP address and spent over and hour with their tech support verifying that it's the right address and there's nothing funny going on. They've used cURL from their command-line as well, but it doesn't work. I tried creating a new key just for that ip, and it still didn't work. I tried a 16-bit IP range, but no dice.
Can someone please shed some light on this? I wish Google provided a list of request IP's in the report so we could verify it's getting the expected IP. Is it possible that the IP was blacklisted by this point somehow?
Thanks!
Had a similar problem. Turned out I had to add the ipv6 to the allowed ips.

Website accessible from everywhere except for client's network

My client has a website that is showing some strange behavior. The site is built in ASP.Net and used to be hosted on their internal network. It's now been moved to a different server outside their network. They have other sites hosted on the same server, some built using DotNetNuke, and some classic ASP. All these sites are hosted on one application server, with a database (SQL Server 2008) on a separate server (which is on the same network as the application server). They share the application server, and the database server.
Now that this site has been moved to the outside server, they can't access it. I can, and so can others that I work with (from different IPs, across the country). But the client can't from their network. They can access the landing page subsite.clientdomain.com (no db access), but nothing else. So, for instance, there's a link to subsite.clientdomain.com/folder. When they click that link, the URL changes to subsite.com/folder, which does not work. For myself and others not at the client site, the URL does not change and opens with no problems.
I didn't write the site, and didn't even know it existed before this problem cropped up, so I know very little more than this. Any help is appreciated.
I'm going to go with Martijn B's answer. There's a DNS issue on the internal network. Somewhere on of the DNS servers is a definition that maps http://companywebsite to an ip address like 192.168.1.20 or whatever.
I would open a command prompt on your PC and type
ping new_website_name.com
Take a look at the IP address that comes back. You can also do an nslookup on new_website_name.com that will give you more information. If you (person A) gets one IP address and Person B (inside the network) gets a different IP address....there is definitely a DNS issue on the internal network.
You're going to have to do some network tracing to determine exactly where any redirection is occurring. Given that the problem is only manifested in certain locations, it is likely that it is a function of network configuration in that location (as previously suggested). Without understanding exactly what redirection is occurring, it would be unwise to make configuration changes that might make the problem worse or introduce new issues.
A DNS server cannot AFAIK redirect to a different URL. So something is redirecting from subsite.clientdomain.com/folder to subsite.com/folder, which could be caused by a HTTP redirect. This can be triggered by the software/website itself or by IIS.

Intermittent 'the remote name could not be resolved'?

I have an ASP.NET application that I use to read the contents of a web page by a HttpWebRequest frequently. There's no problem with the remote address and my application is always working fine.
While I don't change anything, sometimes (about once a day) I get this error:
the remote name could not be resolved.
Why a previously resolved DNS name sometimes fails to be resolved?
The intermittent nature of this is going to be extremely difficult to resolve and it's going to take a configuration change instead of a code solution. (hint: read everything ;)
I would guess that the remote servers DNS is set to expire pretty often. Probably daily or maybe even every 12 hours or so. This is the TTL (time to live) setting. Admins sometimes set this to an artificially low level if they need the ability to quickly move the site to a new server.
You can determine how often it expires by going to a command prompt and running:
nslookup
set debug
www.theserverdomain.com
At the top of this will be a section that says "AUTHORITY RECORDS:" with an item under it that says "ttl".
Now, (and I'm making an educated guess here), what's probably happening when you query your DNS server to resolve that host name your server will have this value cached.
However, once it expires the your server will have to contact another server upstream to get the ip address resolution, called DNS forwarding. If there are a lot of hops between yours and the remote server OR if one of the DNS servers between the sites is overloaded then it could timeout and send back the message you are receiving.
If this is true then the ONLY thing you can do is hardcode the DNS and IP address combination in your web servers hosts file. This is usually at C:\Windows\System32\drivers\etc and is a file named "hosts". There is an example on how to properly edit this within the file itself.
Once you create the host mapping in that file, your web server will no longer have to contact the DNS server to perform name resolution and it won't matter what the TTL is set to.
The only danger here is if they move the web site to a new IP address. At which point you could simply update your hosts file again...
The first thing I would check is if DNS is no longer correctly configured or malfunctioning.
Try (from a Windows command line)
nslookup MyDnsNameHere
and see if you get the IP you would expect.

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