conclusion conclusion DNS ../common/cw/assets/lsnMapConclusion.swf courseMapBtn Course Map Course Map MainMenuButtonClicked lessonMapBtn Lesson Map Lesson Map CourseMapButtonClicked glossaryBtn Glossary Glossary GlossaryButtonClicked resourcesBtn Resources Resources ResourcesButtonClicked exitBtn Exit Exit ExitButtonClicked replayBtn Replay Replay audio ReplayButtonClicked pauseBtn Pause audio Pause audio playback PauseButtonClicked resumeBtn Resume Resume audio playback ResumeButtonClicked previousPgBtn Previous screen PreviousButtonClicked nextPgBtn Next screen NextButtonClicked dnscon_01 1 Welcome to the Maintaining the Domain Name System (DNS) Course conclusion. Let's review some of the key points you have learned in this course. To maintain DNS performance and security, DNS administrators work with configuration and data files and statements, resource record types, control entries, and tools such as nslookup and dig. DNS is vulnerable to attacks. Two primary mechanisms for protecting DNS against security threats are DNSSEC, which stands for Domain Name System Security Extensions, and TSIG, or Transaction Authentication. Although troubleshooting DNS failures is a complex process that depends on the specific scenario, there are a set of more common troubleshooting scenarios that can help guide the process. Systems administrators can apply general guidelines and troubleshooting tools to help resolve the DNS failure they may be facing. Congratulations! You have completed the conclusion to the Maintaining the Domain Name System Course. Screen 1 of 1. Topic Title: Course Conclusion. Screen Title: Summary. Title of the course Maintaining the Domain Name System (DNS) Course appears. Text box appears with bulleted text in support of audio. Checkmarks appear in support of audio.