no functioning dns server available

Generally, the performance and timing problems of dns are caused by suspicious query results. In this case, no matter whether the dns is parsed or not, the consequences are the same. What should we do for actual problems such as long response time, timeout errors, and invalid cache? After all, these types of query responses are still possible to pass. It only requires more time. In fact, in this case, the w

Small to big: Exploring the Security Application of DNS in Enterprise Domain Environments DNS applications within an enterprise are almost ubiquitous. As long as we don't want to remember the pure IP address information You need to use DNS to provide us with simple name memory, such as ing an IP Address: 192.168.10.1 For one, this becomes a good memory, and for

Hosts file), a recursive query request is sent to the specified DNS host, and if the DNS host does not have resolution information for that domain name, it will continually iterate over the DNS host, where the highest level (authoritative) root DNS host has 13 units. The following were:Root

records for a host name are found, it can be used to recycle host resource records that are included in the query answer. By default, the DNS server's services use circular multiplexing to sort resource records that are returned in a reply to a host name that resolves to multiple mappings. This feature provides a very easy way to load balance the use of WEB servers and other frequently queried multihomed computers for clients. For circular multiplex

.(4) record the cache and return the path to the user.Note: In the system, we can track the path through the dig command.Workflow:2. Build a DNS serverToday, we are going to build a DNS server by ourselves. Such requirements are still available within the company.First, find the packages that install dns:Install the

situation. The customer has its own master DNS server and uses the ISP as a secondary server for backup purposes. This type of configuration and almost all other configuration items in BIND are completed through the named. conf file. This file stores server information and zone information in plain text. See Table. Na

In the case where the primary DNS server is functioning properly, configure the slave DNS server on a different server with the same: operation is as follows:We create here DNS from the

is installed. The releasegz is bind-9.4.2.tar.gz.For ease of use in other operating systems, we still install it in the source code package. First from the ISC home page (http://www.isc.org/index.pl? /Sw/bind/index. php) software package.Decompress: # Pwd/Opt/wacos/encle# Gunzip bind-9.4.2.tar.gz# Tar-xvf bind-9.4.2.tar Configure compilation and installation. BIND is normally installed in the/usr/local directory, but you can adjust the -- prefix parameter settings. In this example, IPv6 is not

gradually After successful installation Open Control Panel -- Administrative Tools -- find DNS and click Open -- Forward lookup area. If you want to use doc.mic.cn, right-click the forward lookup area and choose create region. Next, enter the name mic.cn. Create a host Doc in the blank space on the right. The complete domain name is doc.mic.cn. Note: You must create a host name named empty and the complete domain name is mic.cn. To create

Standard DNS software:BIND: Berkeley Internet Name Domain Associated software packages: software packages starting with BindBind-libs provides library files for some peripheral toolsBind-utils client command line toolBIND server package, used to provide DNS ServerBind-chroot, do not install it. This program is very strange.Bind-devel Development KitBind-libbind-d

security risks, because the domain can still be resolved by the parser again and remains available until the next TTL expires. Generally, this is not a big problem, because the TTL value takes effect for a very short time, so the attack domain may only exist for several seconds or several minutes. In this article, we will discuss the recent DNS vulnerabilities in most