I have confirmed with that it's not possible to get DNS Name and environment details (staging vs production) without certificate & management API.
However let's consider my case in that my startuptask(exe) consume REST service to post some data so in that REST service can i do some trick to get DNS name?
I have tried with following
HttpContext.Current.Request.UserHostName however it is same as
HttpContext.Current.Request.UserHostAddress
Please give me suggestion if anyone have you did this type of trick.
Update
Using HostName & HostAddress i am able to get IP of that webrole (confirmed with browser request) but when i try that with nslookup command then it says me that Non-existent domain
Does Azure not support reverse lookup?
Thanks in Advance.
After I study the above details I would say that using above trick, you are getting the external facing VIP address about your service.
Lets consider in that case it would be something as below and if you have port 80 configured with your application you could use this IP address in any browser to verify and you did:
65.52.14.112
Now let's run nslook on IP address and it sure returns what you said:
C:\myTools>nslookup 65.52.14.112
Server: router.belkin
Address: 192.168.2.1
*** router.belkin can't find 65.52.14.112: Non-existent domain
Now for a second lets consider you know the hosted service name (it is my service and I know the name) so lets try to use nslookup with that:
C:\myTools>nslookup azurevmassistant.cloudapp.net
Server: router.belkin
Address: 192.168.2.1
Non-authoritative answer:
Name: azurevmassistant.cloudapp.net
Address: 65.52.14.112
As you can see above the hostname resolves the IP address and that's it. Also you would need to understand in both of the above case you were hitting the Windows Azure loadbalancer not the service itself.
I am able to verify that as of now the Windows Azure does not support "reverse lookup" and if you think that is important it is great chance to let your voice heard and submit the request here: http://www.mygreatwindowsazureidea.com/pages/34192-windows-azure-feature-voting
Related
I was using the Google Stun server by IP 74.125.143.127, but since 21/09/2021 it seems Google changed the IP of DNS stun.l.google.com.
I know I should use DNS rather fixed IP.
Any guys have some confirmation about the IP change?
tks
I know I should use DNS rather fixed IP
Yes. That's the answer. Full stop. Don't hardcode IP addresses to services in your app. The whole point of DNS... well, you know this right?
Some recent DNS lookups:
stun.l.google.com: 74.125.197.127
stun1.l.google.com: 173.194.193.127
stun2.l.google.com: 172.253.112.127
stun3.l.google.com: 173.194.77.127
stun4.l.google.com: 172.217.215.127
Testing the old IP you referenced that's not in the DNS entries above:
>stunclient 74.125.143.127
Binding test: fail
Testing the IP address that's currently being returned:
>stunclient 173.194.193.127
Binding test: success
Local address: 192.168.1.18:55004
Mapped address: 1.2.3.4:55004
I was actually doing some quick labs exercise when I noticed this issue where is ping to an internal IP works but if I ping with machine name it does not work. Here is what I did:
a.) Create a GCP project. Leave all the default firewall rules in place
b.) Create a VM in us-central-1 (any region) call it - mynet-us-vm
c.) Create a VM in eu-west-1 (any region) - call it - mynet-eu-vm
d.) SSH to mynet-us-vm from the console
e.) Run this commands : ping -c 3 <Enter mynet-eu-vm's internal IP here>- It works
f.) Run this command: ping -c 3 mynet-eu-vm - Does not work! Getting below error
Getting Error:
"ping: mynet-eu-vm: Name or service not known"
For Internal DNS resolution to work there are multiple factors that affect this:
On the client Instance running ping the resolv.conf file must have the metadata server (169.254.169.254) as it’s nameserver and the search domains must be set similarly to the example on the documentation, if using a Google provided image this configuration should already be set correctly.
Additionally, verify the hostname registered for the Instance “mynet-eu-vm” this can be done by running curl against the metadata server, the output to this will be the full FQDN which will confirm whether the resolv.conf file should be set to Zonal DNS or Global DNS and if the hostname for the Instance is the same as the one being used with ping.
If running “dig FQDN #169.254.169.254” works but ping still fails this would mean that the Instance is trying to resolve against a different nameserver, or that the search list on resolv.conf is incorrect.
If the above steps fail I suggest raising a support case with Google Cloud Platform or opening a new Public Issue Tracker since following the steps provided does not result in the same behavior and likely it’s something specific to your setup.
I have a standalone, embedded Eureka server powered by Spring Boot 1.2.0.RELEASE and Spring Cloud 1.0.0.RC1. I see services properly registering themselves in the dashboard, which is great. The status links are using the host name of the box they are running on. Unfortunately, we are using virtual machines and they don't register themselves in DNS, which means that the links are unresolvable. I started looking through the code but was unable to find a way to force the links to use the host's ip address instead. Having a broken dashboard is not the end of the world but I am afraid that once we start using Ribbon or Feign to contact services, those URLs will also use the host name and be unresolvable. Maybe what I am really asking is there a way to force the clients to register with an ip address instead of a host name? Any help is appreciated.
set eureka.instance.preferIpAddress=true as documented here
We are currently encountering the following error when trying to connect to a Cloud SQL instance: Lost connection to MySQL server at 'reading initial communication packet', system error: 0.
This is a familiar error, and as detailed here usually means the IP address needs to be whitelisted. However, we believe we have done so.
Is there a way to see connection attempts and their IP addresses that have been made (and refused) to the Cloud SQL instance?
Currently we don't expose that information but it is something we would like fix. :-)
According to #Razvan, as of September 2014, this information isn't exposed.
We ended up using CIDR blocks to search the space and find the actual IP address. This is unsatisfying, obviously, but it's a way to pin down the problem.
If other people want to sanity check that the problem is their IP is being refused, you can add 0.0.0.0/0 in order to accept all ranges and try to connect. If it works, you know what is the problem.
Be absolutely sure to remove this as an accepted range, after you are done, however!
Figured I might help someone who stumbles here.
Had exactly the same issue essentially trying to connect to a GCP SQL instance from a hosting provider.
Whitelist the IP address that is shown in my cpanel and it will not connect. (It used to, but the provider made some changes with their infrastructure lately and it stopped working)
put 0.0.0.0/0 in my Cloud Platform whitelist and it connects no problem.
So now I know that my cpanel IP is not the IP trying to connect to GCP.
After some hair pulling (figured that the bare metal server had a different IP than my cpanel IP, it did, but this also didn't work.)
finally tried the IP address for the name servers that point to my domain and bam. All is good.
If you are facing this issue, try your name server (usually something like NS1.hostingprovider.com etc..). I put both the NS1 and NS2 ip's in the whitelist and we are working fine.
I'm implementing the PASV mode in a FTP server, and I send to the client the IP address and port of the data end point. This is stupid because the IP is actually where the client is already connecting, so there ire two options:
How could I get the public IP
address from a given instance? Not
the VIP, but the public one.
How could I get the original target
IP address that the user used from
a Socket object? Considering routers and load balancers in the middle :P
An answer to any of this questions would do, although there is another way that could work... may I get the public IP address doing a DNS look up of myapp.cloudapp.net?
A fourth option would be use the Azure Management API library... but, too much trouble :P.
Cheers.
Not sure if you ever figured this out, but here's my take on it. The individual role instances are all behind the Windows Azure load balancer and have no idea what the original, outward-facing IP address is. Also, there's no Management API call that returns IP address - Get Deployment returns the URL but not the IP address. I think the only option is going to be a dns lookup.
Having said that: I don't think you can host a passive ftp server in your role instance (at least not elegantly). You may open up to 25 input endpoints on your role (up from 5 - see my recent blog post about this update), but there's manual work involved in the configuration. I don't know if your ftp application lets you limit your port range to such a small number of ports. Also:
You'd have to define each port as its own input endpoint (this is the manual labor part I mentioned) - input endpoints don't allow a port range to be specified, unlike the internal endpoints.
You'd have to specify the port number that's used internally, and the port numbers would need to be sequential
One last thing on ftp: you should be able to host an sftp server with no trouble, since all traffic comes through one port.
The hack that I'm contemplating right now is to retrieve http://www.icanhazip.com/. It isn't elegant and is subject to the availability of that service, but it gets the job done. A better solution would be appreciated!