我最近注意到，BIND一直在/ var / syslog中生成大量与一个特定服务器（ezdns）有关的日志，
Jun 3 03:29:24 overlook named[6586]: success resolving 'ns0.ezdns.tf/AAAA' (in 'ezdns.tf'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:25 overlook named[6586]: success resolving 'ns4.ezdns.tf/A' (in 'ezdns.tf'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:25 overlook named[6586]: success resolving 'ns4.ezdns.tf/AAAA' (in 'ezdns.tf'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:25 overlook named[6586]: success resolving 'ns2.ezdns.tf/A' (in 'ezdns.tf'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:25 overlook named[6586]: success resolving 'ns2.ezdns.tf/AAAA' (in 'ezdns.tf'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:25 overlook named[6586]: success resolving 'ns5.ezdns.tf/A' (in 'ezdns.tf'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:25 overlook named[6586]: success resolving 'ns5.ezdns.tf/AAAA' (in 'ezdns.tf'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:25 overlook named[6586]: success resolving 'ns5.ezdns.ms/A' (in 'ezdns.ms'?) after disabling EDNS Jun 3 03:29:25 overlook named[6586]: success resolving 'ns0.ezdns.pm/AAAA' (in 'ezdns.pm'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:26 overlook named[6586]: success resolving 'ns3.ezdns.yt/AAAA' (in 'ezdns.yt'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:26 overlook named[6586]: success resolving 'ns1.ezdns.pl/A' (in 'ezdns.pl'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:27 overlook named[6586]: success resolving 'ns0.ezdns.it/AAAA' (in 'ezdns.it'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:27 overlook named[6586]: success resolving 'ns1.ezdns.la/AAAA' (in 'ezdns.la'?) after disabling EDNS Jun 3 03:29:27 overlook named[6586]: success resolving 'ns0.ezdns.yt/AAAA' (in 'ezdns.yt'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:28 overlook named[6586]: success resolving 'ns0.ezdns.sx/AAAA' (in 'ezdns.sx'?) after reducing the advertised EDNS UDP packet size to 512 octets Jun 3 03:29:29 overlook named[6586]: success resolving 'ns5.ezdns.ms/AAAA' (in 'ezdns.ms'?) after disabling EDNS Jun 3 03:29:29 overlook named[6586]: success resolving 'ns2.ezdns.pl/A' (in 'ezdns.pl'?) after disabling EDNS Jun 3 03:29:30 overlook named[6586]: success resolving 'ns0.ezdns.sx/AAAA' (in 'ezdns.sx'?) after disabling EDNS Jun 3 03:29:30 overlook named[6586]: success resolving 'ns0.ezdns.yt/AAAA' (in 'ezdns.yt'?) after disabling EDNS Jun 3 03:29:31 overlook named[6586]: success resolving 'ns0.ezdns.ms/AAAA' (in 'ezdns.ms'?) after disabling EDNS Jun 3 03:29:33 overlook named[6586]: success resolving 'ns0.ezdns.ms/AAAA' (in 'ezdns.ms'?) after disabling EDNS 我能做些什么来防止这些日志出现？ 为什么这台服务器是导致BIND生成这些日志的唯一服务器？
我search谷歌，发现隐藏这些日志的几个不同的解决scheme，但我想知道为什么这台服务器是如此麻烦
试着检查一下是否有什么问题导致大于512字节的DNS数据包出现问题。 这不应该是这样的，但有防火墙不正确地不允许这样做。
如果问题不是一直出现在大数据包上，而只是发生在某些特定的远程服务器上，那么这个问题似乎不在你的控制范围之内。
有edns-udp-size （这指定你可以接收到的最大广播包）和max-udp-size （这个指定了你将发送的最大包）选项。 两者都默认为4096.降低这些将增加被截断响应的可能性，并在各自的方向上回退到TCP（一个与recursion更相关，另一个与权威相关）。
但是，如果问题出在您自己的端上，而不是您刚刚遇到一些有问题的随机远程服务器，那么更改这些设置才有意义。 另一方面，如果问题出在您的身上，最好的解决scheme通常是修复导致问题的networking设备，而不是configuration绑定来限制数据包大小。