Red Hat6.5 Failure analysis on the Internet

The RHD HAT6.5 system was installed this morning, and in the morning, the extranet can be accessed, and after the system has been rebooted, a router is added to the network.

The specific configuration is as follows:

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After you change the DNS to point to the gateway, you still cannot access the extranet (the gateway is: 192.168.3.1).

Then change dns,dns again to point to 114.114.114.114 or you cannot access the extranet.

This is not the DNS problem, check whether the intranet can access: (the result is as follows)

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Check that the intranet is OK and check that the network settings are correct:

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Add route add default GW 192.168.192.3.1 Dev eth0 After determining network configuration no problem

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After a period of checking, it was found that there are other gateways in the/etc/sysconfig/network file.

Restore the system to the Add route add default GW 192.168.192.3.1 Dev eth0 before this command.

Modify the/etc/sysconfig/network inside the gateway after normal access to the extranet.

Problem Analysis:

route add default gw  192.168.192.3.1    dev eth0 can access the extranet after this command.

Unable to access the external network troubleshooting ideas:

1. Check if the network IP is in the same segment as the gateway

2. Check if the intranet is able to connect (check intranet correctness)

3. Check the correctness of the gateway configuration

4. Check that DNS is correct

5. Check If the/etc/sysconfig/network file has more than one gateway

The above method is to check that the network cannot access the general steps of the extranet. (PS: There are other ways to check the network failure, not well written, do not update the content after spraying)

Red Hat6.5 Failure analysis on the Internet