DNS related debugging

最新推荐文章于 2025-12-05 14:19:22 发布

最新推荐文章于 2025-12-05 14:19:22 发布 · 75 阅读

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本文介绍如何检查DNS服务器是否运行及监听的IP地址和端口，适用于root用户。同时提供了降低DNS缓存影响的方法，如设置低TTL值，并介绍了如何调整DNS服务器的日志级别和使用rndc命令获取更多信息。

DNS related debugging :

How do I know that the DNS server is running
1. ps –ef | grep named (named is the daemon that runs)
2. As root : netstat –apn | grep named (it will tell you what IP addresses and port are opened by named)
Developers who are making frequent changes to the dns data usually want all their queries to reach the dns server (and not be taken from the cache). Please note you should NOT be doing this in the normal case.
1. Set the TTL to a small value (10 sec) --- $TTL 10 in the named.3gppnetwork.org
Debugging the dns server
1. currently the debug logs are present in /var/cahed/bind/log.msgs .
2. You can change the severity of the logging from “severity info” to “severity debug 3” in named.conf .
3. You can change the severity to “severity dynamic” and then use the rndc commands to try and dump more information: cd /etc/bind; rndc -V -s localhost -k ./rndc.key trace 5; rndc -V -s localhost -k ./rndc.key querylog
4. Currently there dns server does not log when it returns a failure (because it has not data) -- https://lists.isc.org/pipermail/bind-users/2009-January/074973.html
5. The best way is to run a wireshark on eth1 (where the dns server is running). You can even have a capture filter with just dns “port 53”mme