[Solved] Unable to ping Domain Names But Can ping IP on Linux
Configuring DNS
Ensure your Linux server’s DNS configuration file /etc/resolv.conf contains some DNS servers.
If there are no DNS servers in the /etc/resolv.conf, you must add some DNS servers to the file.
vim /etc/resolv.conf |
Add the following content to the file /etc/resolv.conf
nameserver 192.168.0.1 |
You can try to restart your system networking to check whether the problem of being unable to ping domain names is resolved. See the section “Restart Networking” of this post.
Configuring Default Route Gateway
You need to check your route table and check if the destination host 0.0.0.0 is routed to the default gateway IP (e.g. 192.168.0.1). If not you need to update the gateway IP.
Get Default Gateway IP
$ ip r | grep default |
default via 192.168.0.1 dev eth0 proto dhcp metric 100 |
Some computers might have multiple default gateways. The gateway with lowest Metric is the first to be searched and used as the default gateway.
My server’s default gateway IP is 192.168.0.1.
Check the Route Table
Print the route table:
$ sudo route -n |
Kernel IP routing table |
- Destination: The destination network or destination host.
- Gateway: The gateway address or ’*’ if none set.
- Genmask: The netmask for the destination net: 255.255.255.255 for a host destination and 0.0.0.0 for the default route.
What Is The Meaning of 0.0.0.0 In Routing Table?
Each network host has a default route for each network card. This will create a 0.0.0.0 route for such card. The address 0.0.0.0 generally means “any address”. If a packet destination doesn’t match an individual address in the table, it must match a 0.0.0.0 gateway address. In other words, default gateway is always pointed by 0.0.0.0
Update the 0.0.0.0 Route to the Default Gateway
Update the destination host 0.0.0.0 route the the default gateway IP e.g 192.168.0.1.
ip command
You can temporarily update the 0.0.0.0 route gateway by the ip command.
Add the default route:
ip route add default via 192.168.0.1 |
You can also delete the default route:
ip route delete default |
route command
You can temporarily update the 0.0.0.0 route gateway by the route command.
Add the default route:
route add default gw 192.168.0.1 |
You can also delete the default route:
route del default gw 192.168.0.1 |
Update configuration file
You can permanently update the 0.0.0.0 route gateway by in system configuration file.
CentOS/RHEL
vim /etc/sysconfig/network |
Add the following content to the file /etc/sysconfig/network
NETWORKING=yes |
Debian/Ubuntu
vim /etc/network/interfaces |
Find network interface and add the following option
... |
Restart Networking
After update the gateway configuration file, you need restart the networking.
Restart the networking on CentOS/RHEL
sudo systemctl restart NetworkManager.service |
Restart the networking on Debian/Ubuntu
sudo /etc/init.d/networking restart |
Appendixes
Some public DNS servers
# OpenDNS |