Weird dns issue when SSHing with git push

sanjibukai · 05-18-2018, 01:35 AM

Hi everybody,

I have a weird issue I cannot figure out..
I have a git repository with an origin remote to some url (eg.

Code:

git@example.com

)
When I make a ping request

Code:

ping example.com

I receive the response with the actual IP address..
However when I try to SSH (or even when I try to git push) I get the following error:

Code:

ssh: connect to host 172.17.0.2 port 22: No route to host
ssh_exchange_identification: Connection closed by remote host

I don't know why I got that private IP?
As I said, the ping works with the actual IP..
In an another PC on my LAN I don't have this problem.

How can I troubleshot this issue?

I am running manjaro in a virtualbox

/dev/random · 05-18-2018, 01:14 PM

Quote:

Originally Posted by sanjibukai

Hi everybody,

I have a weird issue I cannot figure out..
I have a git repository with an origin remote to some url (eg.

Code:

git@example.com

)
When I make a ping request

Code:

ping example.com

I receive the response with the actual IP address..
However when I try to SSH (or even when I try to git push) I get the following error:

Code:

ssh: connect to host 172.17.0.2 port 22: No route to host
ssh_exchange_identification: Connection closed by remote host

I don't know why I got that private IP?
As I said, the ping works with the actual IP..
In an another PC on my LAN I don't have this problem.

How can I troubleshot this issue?

I am running manjaro in a virtualbox

When you git push is the remote origin a ip address or a dns name?
From the little output shown, it seems your box got its arp cache poisoned somehow.

sanjibukai · 05-18-2018, 02:08 PM

Hi,
Here is the output of my remote list:

Code:

origin git@example.com:project (fetch)
origin git@example.com:project (push)

When I do a git push I got the previous error message where the host is replaced by that IP address..

Code:

ssh: connect to host 172.17.0.2 port 22: No route to host

However, when I do a ping or even an nslookup I got the real IP address as it should be:

Code:

> nslookup example.com

Server:		192.168.0.1
Address:	192.168.0.1#53

Non-authoritative answer:
Name:	example.com
Address: 75.126.162.205

> ping example.com

PING example.com (75.126.162.205) 56(84) bytes of data.

In both these cases I got my real IP..

How can I check (reset) the arp cache ?

Edit:
I found this link https://www.orionscache.com/2014/01/...ache-in-linux/
When I listed the arp cache at first I got this:

Code:

>arp -n
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.0.1              ether   18:d6:c7:xx:xx:xx   C                     enp0s3
172.17.0.3               ether   02:42:ac:xx:xx:x3   C                     docker0
172.17.0.2               ether   02:42:ac:xx:xx:x2   C                     docker0

Then I flushed the cache and I got one line deleted:

Code:

>ip -s -s neigh flush all
..
..
*** Round 1, deleting 5 entries ***
*** Flush is complete after 1 round ***
>arp -n
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.0.1              ether   18:d6:c7:xx:xx:xx   C                     enp0s3
172.17.0.2               ether   02:42:ac:xx:xx:x2   C                     docker0

But the result stay the same...
And in fact, that weird address has to do with docker?
I don't know why...

Edit 2:
Also, since I'm running arch (manjaro), it seems I don't have a dns cache..

/dev/random · 05-18-2018, 03:13 PM

Quote:

Originally Posted by sanjibukai

Hi,
Here is the output of my remote list:

Code:

origin git@example.com:project (fetch)
origin git@example.com:project (push)

When I do a git push I got the previous error message where the host is replaced by that IP address..

Code:

ssh: connect to host 172.17.0.2 port 22: No route to host

However, when I do a ping or even an nslookup I got the real IP address as it should be:

Code:

> nslookup example.com

Server:		192.168.0.1
Address:	192.168.0.1#53

Non-authoritative answer:
Name:	example.com
Address: 75.126.162.205

> ping example.com

PING example.com (75.126.162.205) 56(84) bytes of data.

In both these cases I got my real IP..

How can I check (reset) the arp cache ?

Edit:
I found this link https://www.orionscache.com/2014/01/...ache-in-linux/
When I listed the arp cache at first I got this:

Code:

>arp -n
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.0.1              ether   18:d6:c7:xx:xx:xx   C                     enp0s3
172.17.0.3               ether   02:42:ac:xx:xx:x3   C                     docker0
172.17.0.2               ether   02:42:ac:xx:xx:x2   C                     docker0

Then I flushed the cache and I got one line deleted:

Code:

>ip -s -s neigh flush all
..
..
*** Round 1, deleting 5 entries ***
*** Flush is complete after 1 round ***
>arp -n
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.0.1              ether   18:d6:c7:xx:xx:xx   C                     enp0s3
172.17.0.2               ether   02:42:ac:xx:xx:x2   C                     docker0

But the result stay the same...
And in fact, that weird address has to do with docker?
I don't know why...

Edit 2:
Also, since I'm running arch (manjaro), it seems I don't have a dns cache..

What happens when you do the following:

Code:

origin git@75.126.162.205:project (fetch)
origin git@75.126.162.205:project (push)

Also what is the output of:

Code:

 route -n

sanjibukai · 05-18-2018, 09:35 PM

Hello again,
Indeed, replacing the remote with the IP worked (as SSHing using the IP).
Should be some weird DNS issue then..

The output of the route is:

Code:

>route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.0.1     0.0.0.0         UG    100    0        0 enp0s3
172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0
192.168.0.0     0.0.0.0         255.255.255.0   U     100    0        0 enp0s3