I have a weird problem I can't solve due to my lack of knowledge.
I have a local server running Dnsmasq. On my computer (Windows 10) I have Acrylic DNS Proxy which directs all requests ending with .local to the local server. It works great, however one domain respons with an unknown IPv6 address.
> ping testdomain.local
Pinging TESTDOMAIN [IPv6 address] with 32 bytes of data:
Reply from IPv6 address: time<1ms
I can't figure out why testdomain.local is reversed to TESTDOMAIN. All my other local domains respons as expected:
> ping testdomain2.local
Pinging testdomain2.local [local server address] with 32 bytes of data:
Reply from local server address: bytes=32 time<1ms TTL=64
Related
I installed ubuntu-server in Virt-Management.
I cannot get a response using the following command
ubuntu-server ip: 10.0.2.15
my host ip : 192.168.124.10
ping 10.0.2.15
PING 10.0.2.15 (10.0.2.15) 56(84) 字节的数据。
But ubuntu can get a response
Please see the picture below
I use MacOS 10.14.6 and few days ago I faced with a problem on my computer with localhost.
Rubymine can't connect to database with an error "java.net.NoRouteToHostException: Can't assign requested address (Address not available).". Also when I run puma server on 0.0.0.0:3000, browser can't open page on this address, and when I run server on 127.0.0.1:3000, browser can't open page on this address too, but can open on localhost:3000. I ran ping and got this output:
PING 127.0.0.1 (127.0.0.1): 56 data bytes
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
Request timeout for icmp_seq 0
ping: sendto: Can't assign requested address
Request timeout for icmp_seq 1
ping: sendto: Can't assign requested address
Request timeout for icmp_seq 2
ping: sendto: Can't assign requested address
Request timeout for icmp_seq 3
^C
--- 127.0.0.1 ping statistics ---
5 packets transmitted, 0 packets received, 100.0% packet loss```
WARP was the cause of the problem. Issue started after disabling the app. Disabling and reboot or enabling the app resolved the issue.
Just was walking around till I tried to ping a domain .
But I surprised that it was the domain of the localhost !
I went to see what the wrong was , and how this domain set itself .
However,I didn't find anything that related to it in the localhost OS !
I tried to ping it via online ping service , and the surprise is here , it pings the localhost of the service host !
The domain is :
securitytube.com
Is there any explanation ?
This should be migrated to superuser but the answer to your question is because the owners of that domain have an IP address of 0.0.0.0 set...
$host securitytube.com
securitytube.com has address 0.0.0.0
securitytube.com mail is handled by 0 mail.happyisp.com.
$ping securitytube.com
PING securitytube.com (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost.localdomain (127.0.0.1): icmp_seq=1 ttl=64 time=0.089 ms
Most linux boxes will presume that's the loop-back address (Hence return 127.0.0.1) Windows boxes appear to not do anything other than error out.
c:\ping 0.0.0.0
Pinging 0.0.0.0 with 32 bytes of data:
PING: transmit failed. General failure.
I encountered this strange behavior today I could not find a cause for. I am using MacOS Sierra.
I have this code (Express):
app.server.listen(config.port, config.address, function () {
logger.info('app is listening on', config.address + ':' + config.port);
});
And it prints
app is listening on 127.0.0.1:5000
How ever, if I try to curl, it fails.
$ curl http://localhost:5000/api/ping
curl: (56) Recv failure: Connection reset by peer
I checked my hosts file:
$ cat /etc/hosts
##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting. Do not change this entry.
##
127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost
So I ping localhost to make sure it resolves to 127.0.0.1:
$ ping localhost
PING localhost (127.0.0.1): 56 data bytes
64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.061 ms
64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.126 ms
64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.135 ms
^C
--- localhost ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.061/0.107/0.135/0.033 ms
I try again, but it fails
$ curl http://localhost:5000/api/ping
curl: (56) Recv failure: Connection reset by peer
Now I try to use 127.0.0.1 instead and voila, it works?
$ curl http://127.0.0.1:5000/api/ping
pong
What's wrong?
cURL is trying to connect via IPv6 but your Express server is listening on 127.0.0.1 which is IPv4.
You can force cURL to connect via IPv4 with the -4 option.
curl -4 http://127.0.0.1:5000/api/ping
I understand that say putting in the following:
127.0.0.1 some.machine.com
into a hosts file will force some.machine.com resolve locally.
What if I do not want a specific url not to resolve at all? say "dev/null"
You can apply the same logic to negate an URL from resolving which you actually did allow to resolve.
For example, I blocked
www.TechBeamers.com
Update the host file with the following entry:
1.1.1.1 www.TechBeamers.com
Before updating the host file:
Pinging www.TechBeamers.com [xyz.xx.yy.xyz] with 32 bytes of data:
Reply from xyz.xx.yy.xyz: bytes=32 time=304ms TTL=50
Reply from xyz.xx.yy.xyz: bytes=32 time=293ms TTL=50
Post updating the host file:
Pinging www.TechBeamers.com [1.1.1.1] with 32 bytes of data:
Request timed out.
Request timed out.