I tried to connect to my wifi network but i am not able to connect through my laptop .My other device at home are able to connect to internet. I am using ubuntu 16.04 LTS . I set my browser proxy to no proxy . I have no antivirus installed .
I tried to ping -c 5 (google .com and facebook.com) in terminal its showing unknown host google.com and unknown host facebook.com and tried to install eclipse while downloading it shows error java error unknown host .
Please help me to solve this issue.
Sounds like DNS may not have been configured when you connected to the network. This should normally happen automatically, but you can check by looking at the file /etc/resolv.conf. There should be at least one line in the file containing nameserver and an IP address.
If there are no nameserver lines, or if there's only one and it says nameserver 127.0.0.1, then you can try to use Google's public DNS by adding the line nameserver 8.8.8.8 (replacing the 127.0.0.1 if that's present).
Like everyone, I had to face this issue. So what did I do to address this issue?
1) I configured my Ubuntu server to have two network interfaces (NAT and Intnet).
2) In /etc/network/interfaces , I added the following lines:
auto enp0s8
iface enp0s8 inet static
address 192.168.10.23
dns-nameservers 8.8.8.8 8.8.4.4
3) Restarted the network - /etc/init.d/networking restart
Result: ping google.com worked.
I hope this helps you in resolving this issue :)
Related
I recently upgraded my virtual machines to Ubuntu 16.04 LTS from 14.04 LTS and couldn't get DNS to work.
nsloookup
;; connection timed out; no servers could be reached
Tried the following but still the issue is there:
https://willhaley.com/blog/resolvconf-dns-issue-after-ubuntu-xenial-upgrade/
http://www.ubuntugeek.com/fix-for-dns-problems-after-upgrading-from-ubuntu-16-04-to-ubuntu-16-10.html
something to add here.
ok something to add here.
I set up a tcp dump on the my machine with
sudo tcpdump -n -i eth0 | grep xx.xx.xx.xx.53 (where xx.xx.xx.xx is the ip address of the proxy server)
I don't get a response back as below
21:29:55.150092 IP yy.yy.yy.yy.37459 > xx.xx.xx.xx..53: 4219+ [1au] A? www.google.com. (43)
21:30:00.150044 IP yy.yy.yy.yy.37459 > xx.xx.xx.xx..53: 4219+ [1au] A? www.google.com. (43)
21:30:05.150172 IP yy.yy.yy.yy.37459 > xx.xx.xx.xx..53: 4219+ [1au] A? www.google.com. (43)
Firewall rules seems to be fine.
Any help would be greatly appreciated.
Ok I get it working now. The main issue was, the latest version of dnsmasq on Ubuntu 16.04 by default only allows responses within the same subnet, in order to allow multiple subnets I need to add
interface=*
to my /etc/dnsmasq.d/10-local-dns-server file.
This resolved the issue.
Running opensuse tumbleweed with 4.7.5-1-default kernel and gnome.
Network managed with gnome's network-manager. Network (wired and wireless) connect to my router.
ping works also to external IPs
dig works if I provide the dns ip (eg. 8.8.8.8)
nmcli dev show | grep DNS shows the right nameservers (which I set in
the network managers interface): 8.8.8.8 and 8.8.4.4,
but dig without specification of the dns IP does not work
ping etc. to internet names (e.g. google.com) does not work.
Am completely lost by now. Help greatly appreciated.
(Matt stated the solution in his comment but I failed to understand it.)
Solution found on opensuse forum: the /etc/resolve.conf file was corrupted (empty). After deleting it and rebooting, the system (network-manager?) generated a new, working version. It contains the ip of the nameserver.
How do I exclude DNS from the DHCP lease request on a Raspberry Pi?
I tried updating /etc/resolv.conf but it's reset after a while.
Reason: I am on a home network, and the home router uses itself as the DNS server, but the router's DNS service isn't working properly sometimes.
Most of the answers didn't work for me, but I found that this worked:
sudo vi /etc/dhcpcd.conf
Added a line (note that there is no comma):
static domain_name_servers=8.8.8.8 8.8.4.4
And unplugged and replugged my ethernet cable, which updates the resolver...
cat /etc/resolv.conf
Now shows:
# Generated by resolvconf
domain example.com
nameserver 8.8.8.8
nameserver 8.8.4.4
This also a better way to fix the problem where changes to /etc/resolv.conf are lost on reboot.
I asume the problem is, that the dhcpclient is getting new information about DNS servers with every dhcp-renewal. Add this line into /etc/dhcp/dhclient.conf:
option domain-name-servers 192.168.1.8, 8.8.8.8, 8.8.4.4
Of course you should replace the ip-addresses with the ones from your demanded DNS server. Probably restart the according service.
Hi StackOverflow members,
I have an issue with ssh connection on my Debian 7 system to a remote OpenSSH server located on the same network. It looks like there is some network configuration problem but I cann't find where it lays. This two debian machines are connect with a switch that is NOT connected to a router. So the two machines have no internet connection.
A-Debian 7
IP: 192.168.1.2
MASK: 255.255.255.0
GW: 192.168.1.1
B-Debian 7
IP: 192.168.1.3
MASK: 255.255.255.0
GW: 192.168.1.1
With that configuration the ssh command prompts my for a password in less then a second. But the with the following network configuration I get the password prompt after a 10+ second delay:
A-Debian 7
IP: 10.10.1.83
MASK: 255.255.255.128
GW: 10.10.1.1
B-Debian 7
IP: 10.10.1.82
MASK: 255.255.255.128
GW: 10.10.1.1
The ssh connection from the server A -> B runs with both configs on custom 1111 port.
The B machine has also a Web server running on port 8080 that has no delays with both net configurations.
Thank you in advance for any clues or tips how to solve that problem.
SOLVED: Removing of the gateway parameter "GW: 10.10.1.1" in the network settings has solved the problem.
The usual culprits here are IPv6 and DNS lookups.
SSH might try to connect via IPv6, first, but the timeout is too low for that. You can see whether IPv6 is enabled with
cat /proc/sys/net/ipv6/conf/eth0/disable_ipv6
To disable:
echo 1 > /proc/sys/net/ipv6/conf/eth0/disable_ipv6
The second culprit is DNS; my guess is that DNS lookups don't work correctly with the second configuration. Try host www.google.com to test this theory.
If that also has a delay, you need to fix your DNS setup.
If that's not it, check the rest of your networking parameters: Gateway, cables, etc.
Start to ping the other host. Is that fast & reliable?
Next, try remote login (ssh, telnet). Note that you can give telnet a port to connect to, so if you have DB server running, you can still use telnet to connect to the server. It will print an error but it allows you to test the TCP/IP connection without any extra error sources.
I Have Window 7 as Host Machine and I have installed Redhat 5.3 and Centos 5.4 as Vmware Machines under Window 7 through Vmware Workestation.I configure DNS & DHCP in Redhat 5.3(10.0.0.1) and able to do nslookup & DIG in this.I am able to ping window 7,redhat,centos with each other.
I have made one entry client30.example.com for ip 10.0.0.30 in forword and backword lookup file in DNS server(10.0.0.1).
Problem :-
Centos whom i have made dhcp client of Redhat(10.0.0.1) is able to get ip from dhcp server and it gets ip 10.0.0.30 (as i wanted no problem till now)
But Centos is not picking up hostanme client30.example.com as i have bind entry of ip 10.0.0.30 with client30.example.com.
Still it is picking up hostname localhost.localdomain. I check /etc/resolve.conf file of centos and i found that by default it picks nameserver 192.168.1.1(even i have not provided this ip anywhere).Everytime i made manual change in this ip again it pics same ip on reboot.
Kindly help how i can resolve this problem.
Because VMware Workstation is itself DHCP. Please disable DHCP in VMware Workstation, You can't run two DHCP in single network subnet.
Also check /etc/sysconfig/network file, Hostname coming from there.