Knowledge Base ISC Main Website Ask a Question/Contact ISC
Quick Jump Menu
Categories
There are no subcategories in this category.
41 DNS Cache snooping - should I be concerned?

DNS cache snooping is a technique that can be employed for different purposes by those seeking to benefit from knowledge of what queries have been made of a recursive DNS server by its clients. Uses of this information vary, ranging from planning which mis-typed…

42 Background info about 'maximum number of FD events' log messages

Log messages reading maximum number of FD events received mean that when checking to see whether any sockets were ready to be read from, named found that there were more than 64 of them. These log messages are not related to the maximum number of open file…

43 How does clients-per-query work?

Question: How does clients-per-query work when named is running? There is often confusion over clients-per-query, especially when encountering logfile entries such as these below: 10-May-2011 13:01:02.745 resolver: notice: clients-per-query increased to 20…

44 Considerations when choosing and configuring Load Balancers

Question: What sort of features and functionality should be borne in mind when choosing and configuring a Load Balancer, either to spread the load of recursive queries between a number of recursive servers, or to provide authoritative DNS replies based on…

45 Defining a named.conf ACL for 'any IPv6' address

Question: Is there a built-in ACL for named.conf that is for any IPv6 address? Answer: The following ACL definitions are for all IPv6 and all IPv4 addresses respectively: acl any6 { ::0/0; }; acl any4 { 0.0.0.0/0; };

46 What does "isc_socket_create: fcntl//rreserved: Too many open files" mean?

Question: What do these named errors signify - and how should they be investigated? 10-May-2011 15:41:13.815 general: error: isc_socket_create: fcntl/reserved: Too many open files 10-May-2011 15:41:13.815 general: error: isc_socket_create: fcntl/reserved:…

47 Why does rndc reconfig sometimes resolve recursive server problems with some domains?

There are many poorly-configured DNS servers that provide records that break the the DNS protocols. Depending on how poorly these servers comply, name resolution may work most of the the time. Factors influencing this include the relative TTLs of parent and…

48 How to verify a clean network path for DNS resolution by recursive servers

This article only applies to BIND version prior to 9.10 BIND 9.10 (and more recent) uses a different EDNS probing algorithm that doesn't work with the current set of existing rs.dns-oarc.net records. ISC does not currently know of any similar set of records…

49 Building BIND for Solaris

BIND is a direct drop-in for the default Solaris distribution if it is built with the following configure options (in addition to any other options that you need): --prefix=/usr --with-libtool --bindir=/usr/sbin --sbindir=/usr/sbin --libdir=/usr/lib/dns --sysconfdir=/etc…