Java dns router

Crypto IPsec client EZVPN profile to use the ACLs. SUMMARY STEPS 1. enable 2. configure terminal 3. interface interface-name 4. exit 5. crypto ipsec client ezvpn name 6. acl {acl-name | acl-number} DETAILED STEPS Command or Action Purpose Step 1 enable Example: Router> enable Enables privileged EXEC mode. Enter your password if prompted. Step 2 configure terminal Example: Router# configure terminal Enters global configuration mode. Step 3 interface interface-name Example: Router (config)# interface Ethernet1 Selects the interface you want to configure by specifying the interface name and enters interface configuration mode. Step 4 exit Example: Router (config-if)# exit Exits interface configuration mode. Step 5 crypto ipsec client ezvpn name Example: Router (config)# crypto ipsec client ezvpn ez1 Creates a Cisco Easy VPN remote configuration and enters crypto Easy VPN configuration mode. Step 6 acl {acl-name | acl-number} Example: Router (config-crypto-ezvpn)# acl acl-list1 Specifies multiple subnets in a VPN tunnel. Configuring Proxy DNS Server Support As a way of implementing the use of the DNS addresses of the ISP when the WAN connection is down, the router in a Cisco Easy VPN remote configuration can be configured to act as a proxy DNS server. To enable the proxy DNS server functionality with the ip dns server command, perform the following steps. SUMMARY STEPS 1. enable 2. configure terminal 3. ip dns server DETAILED STEPS Command or Action Purpose Step 1 enable Example: Router> enable Enables privileged EXEC mode. Enter your password if prompted. Step 2 configure terminal Example: Router# configure terminal Enters global configuration mode. Step 3 ip dns server Example: Router (config)# ip dns server Enables the router to act as a proxy DNS server. Note This definition is IOS specific. What to Do Next What to Do Next After configuring the router, you configure the Cisco IOS Easy VPN server as follows: Under the crypto isakmp client configuration group command, configure the dns command as in the following example: dns A.B.C.D A1.B1.C1.D1 These DNS server addresses should be pushed from the server to the Cisco Easy VPN remote and dynamically added to or deleted from the running configuration of

DNS Reconfiguration GuideHow to change your system's DNS Settings.“You can't optimize it until you can measure it”And once you've measured it, you might want to change it!Before we can meaningfully discuss reconfiguring your system's or network's domain name server (DNS) operation, we need to discuss all the ways it might currently be configured. Any of the following situations might be possible:Small Office / Home Network DNS ConfigurationsAutomatically configured machine, with no router:Without any form of NAT router (see “NAT?” below) interposed between your computer and its connection to the Internet, and unless your computer's Internet address and DNS server settings have been manually changed, the two DNS servers configured for your computer's use will be automatically assigned by your Internet service provider (ISP) each time the computer is started. In such cases, the IP addresses of those DNS servers will be for DNS servers provided by, and probably operated by, your ISP.NAT? Although you may be accustomed to simply calling a router a “router,” the formal name is “NAT router,” where NAT is an abbreviation standing for Network Address Translation. All typical SOHO (Small Office / Home Office) residential routers are “NAT routers,” so this is how they are referred to here.Manually configured machine, with no router:Although it is never the default configuration, it is possible for your computer's automatic DNS server assignment to be manually “overridden” by providing one or more specific DNS resolver IP addresses that will cause the computer to ignore the default addresses that would otherwise be provided by your Internet connection's ISP.Automatically configured machine — with public or private DNS IPs — behind a router:When any NAT router is present to interconnect your Local Area Network (LAN) to the Internet (WAN - Wide Area Network), the router obtains a public IP address for the network, as well as some number of (usually two) public IP addresses for DNS resolvers. Then, when any computer connected to the local network is turned on, unless that computer's settings have been manually configured (see next option below), each computer “behind” the router will, in turn, obtain a “local” (private network) IP address for its use, as well as one or more DNS resolver IPs.Some routers pass the two public DNS IPs obtained from the ISP through to the machines located on the LAN, whereas other routers provide their own private IP on the LAN, the so-called “gateway IP,” as the IP to be used for DNS resolution by the LAN's computers. In the case of public DNS resolver IPs, the machines on the LAN send their queries directly to the publicly located DNS resolvers for resolution. In the case of having received the router's own private LAN IP for DNS resolution, machines on the LAN behind the router will send their DNS queries to the router, believing it to be a DNS resolver when, in fact, the router operates as a “proxy” for the actual public DNS resolvers. The router forwards any received DNS queries to the actual DNS

Here are 36 public repositories matching this topic... Code Issues Pull requests Solve your DNS hosts from your docker containers, then from your local configuration, then from internet Updated Feb 24, 2025 Java Code Issues Pull requests The DuckDNS DDNS Server Code Updated Jun 13, 2018 Java Code Issues Pull requests A set of core libraries for Java Updated Mar 11, 2025 Java Code Issues Pull requests Eureka DNS Server: RFC 1035/2782 compatible DNS server interface to Netflix Eureka service registry. Updated Apr 19, 2022 Java Code Issues Pull requests A Secure DNS Server (forwarder) based on Google DNS over HTTPS Service Updated Sep 16, 2017 Java Code Issues Pull requests A simple DNS server that gets a hostname from a client and returns the hostname's IP address Updated Dec 30, 2019 Java Code Issues Pull requests A tool to manipulate web pages on behalf of the visitor. Updated Aug 28, 2018 Java Code Issues Pull requests A java DNS proxy server that filters huge list of domain names Updated Sep 19, 2018 Java Code Issues Pull requests Pollution free high performance DNS service Updated May 4, 2017 Java Code Issues Pull requests Authoritative DNS Server and Service Registry with Resource Record versioning Updated Nov 14, 2018 Java Code Issues Pull requests JavaScript-configurable, lightweight, authoritative, non-recursive DNS server in Java. Updated Jan 14, 2019 Java Code Issues Pull requests computer network Updated Feb 14, 2023 Java Code Issues Pull requests Basic DNS system implementation using Java Updated Apr 17, 2023 Java Code Issues Pull requests Enhances Netty's DNS support with the ability to parse and programmatically manipulate DNS records with a clean API Updated Jun 12, 2023 Java Code Issues Pull requests DNS Log Analyzer is a multithreaded Java application that monitors and analyzes log files generated by a DNS

Configuration interface, is to have the router distribute public DNS resolver IPs to the machines on its network — as opposed to giving them its own private IP for DNS resolution. When that is done, the network's computers directly query their public DNS servers, rather than querying the router. But, as was explained above, by default many routers now issue their own local IP as the DNS server for the network, then “proxy” the DNS queries from the local network's computers. Unfortunately, it appears that common, inexpensive, consumer-grade routers don't do a very good job of handling DNS for the machines on their networks: During the development of GRC's DNS Spoofability tests, we discovered that many inexpensive consumer-grade routers could be crashed merely by handling complex but valid DNS queries. This makes us wonder whether there might be some means for remotely “taking over,” rather than crashing, such malfunctioning routers. That would not be good.Note: We determined what was causing the router crashes and developed a specific router crashability test, while also managing to avoid crashing even the crashable routers during regular spoofability testing. You may wish to verify that your router is not “crashable” for the reasons given above.But the larger concern is that the error-handling and retrying logic used by inexpensive routers for unanswered DNS queries is unknown and likely to be poor. Modern computers have a mature, time-tested and sophisticated system for retrying unanswered or too-long-delayed DNS queries. We like the idea of allowing that mature technology to function. But if the router is “proxying” the computer's DNS query our DNS handling is at the router's mercy. That seems wrong and less than optimal.Therefore, if you prefer to have your network's router centrally manage DNS for your computers, you might wish to see whether it's possible to have the router distribute the public DNS resolver IPs that you specify, rather than having it providing its own gateway IP as the network's DNS. That just seems a lot better, cleaner, and simpler.Pros & Cons of Individual Per-computer DNS:By “per-computer DNS” we mean that you will manually configure the DNS settings of specific computers, providing them with the IP addresses of two or more public DNS resolvers. This is easily done by instructing your computer to obtain the machine's own IP address for itself from the router (if any) but not to get its DNS servers automatically. One reason for doing this is to allow one computer on the network to experiment for a while with alternative DNS resolvers while leaving the rest of the network as it was . . . until you gain some confidence in the performance and reliability of the alternative resolvers you're using.Then, once you have determined the best DNS resolvers for your use, you might consider reconfiguring your network's router to provide the IPs of these optimal DNS resolvers to all of the computers on your network.Performance difference? What about the relative performance of the “router proxy” configuration (where the network's computers use

This, then rather than having all of your DNS queries sent to an ISP's resolvers for resolution, the effects of your DNS queries would be spread out across the Internet as your own DNS resolver directly queried the Internet's DNS servers for the IPs your computer(s) required. While it is possible for individuals to setup their own DNS resolvers — and advanced Internet users do so — doing this is beyond the scope of these pages. We just wanted you to know that the possibility existed.“DNS Spoofing” is a powerful means for trickingunsuspecting users to visit fake (spoofed) web sites:After changing your system's DNS providers, you should use GRC's freeDNS Spoofability system to verify that your new DNS provider hasconfigured their DNS resolvers to thwart DNS spoofing exploits.A quick Google search on the phrase “DNS Spoofing” (perform search with this link) will reveal that the threat is real and very well understood. Despite this fact, it is estimated that upwards of 25% of the Internet's DNS servers are currently (in 2010) vulnerable to DNS spoofing vulnerabilities. GRC created its free DNS Spoofability testing system to allow Internet users to quickly check their own DNS provider's current “spoofability,” as well as to expose those DNS providers who had still not updated their configurations and to (hopefully) put some pressure on them to finally do so.Needless to say, you do not want to mistakenly use any DNS resolvers that might be exploited to return the wrong IP address for a domain you visit — such as your online banking institution — which could cause you to expose your financial logon credentials and other confidential information to unscrupulous and malicious criminals.We are not aware of any other system, besides the one offered by GRC, which provides a sophisticated analysis of the state of DNS resolver “spoofability.” PLEASE be sure to take advantage of its services. It is both fast and free.What DNS Configuration is Best?Now that you have some sense for the several possible DNS configuration arrangements, and for the consequences of changing your current DNS setup, let's examine how to go about making these changes. Assuming you have a router, as users with small networks will, the question to answer is whether you want your DNS configuration to use the centralized router-based approach (if offered by your router) or whether you'd prefer to have your network's computers use public DNS servers directly.Pros & Cons of Router-based DNS:If your computer(s) is/are not behind a router, then router-based DNS is not an option. But assuming that you do have a router, the greatest benefit offered by router-based DNS is that the DNS servers within your entire network can be “centrally managed” and completely changed at a single location (within the router.) This makes experimenting with alternative DNS servers easier, so long as you don't mind having every machine on your network all switching to the new DNS at once.It has been our experience that the best approach, if it is available from the router's