Master Tips DNS Server Fast error-in-line

We should remember the two large-scale network-breaking events that occurred in China in the June. After analysis, both of these network events originated from the hacker's DNS server attack on the ISP caused by the domain name resolution storm. Thus, the importance of DNS servers for network operations. Similarly, DNS is also a very critical server in the current enterprise LAN. If the DNS server fails, it will have a significant impact on the enterprise LAN, or even paralysis. A DNS server based on the Wndows Server 2008 platform is undoubtedly the best solution, but what are the areas where mistakes should be made? This article will share with you 5 very important debugging skills.

1, from the check server's TCP/IP configuration began

In DNS errors, there are more TCP/IP related, so our first priority should start with checking the TCP/IP configuration of the server. Go to the TCP/IP configuration window of the server, check and verify that its settings are incorrect, and restore the correct settings if it is incorrect. The author's experience, we recommend that after configuring DNS, not only to backup the DNS configuration, but also to the server's TCP/IP settings for backup, so that the recovery is very convenient. Executing the command "netsh interface dump>c:\settings.txt" at a command prompt on the server will back up its TCP/IP settings to the Settings.txt file under C disk. If you want to restore the executable command "netsh exec C:\settings.txt" can be. If the DNS error persists after restoring or reconfiguring TCP/IP, we can proceed with the following row error. (Figure 1)

2, do not ignore the server's cache

Like DNS clients, DNS servers also have their own resolution caches, which are often ignored by admin. This cache on the DNS server is primarily used to respond to queries that are frequently performed (which may be required by the client or that the server itself needs) to resolve query logging requirements. If we suspect that a DNS server failure is caused by an old record, the command "DNSCmd Servername/zoneprint" can be executed at the command prompt. To view the caching of the DNS server. "ServerName" in this command is the name or IP address of the DNS server, "." Indicates that we are looking at the server's cache, which contains the root name server that is used by the server.

By looking at the server cache, the administrator can make a decision accordingly. If necessary, we can force the server to empty its cache. To do this, you can right-click the server item in the DNS console and select the Clear Cache command. In addition, we can also clear the server cache by executing the command "DNSCmd Servername/clearcache" at the command line. where servername is the name or IP address of the DNS server to clear the cache. (Figure 2)