How to Implement Forward DNS Look Up Cache? - GeeksforGeeks

How to Implement Forward DNS Look Up Cache? - GeeksforGeeks

How to Implement Forward DNS Look Up Cache? We have discussed implementation of Reverse DNS Look Up Cache . Forward DNS look up is getting IP address for a given domain name typed in the web browser. The cache should do the following operations : 1. Add a mapping from URL to IP address 2. Find IP address for a given URL. There are a few changes from reverse DNS look up cache that we need to incorporate. 1. Instead of [0-9] and (.) dot we need to take care of [A-Z], [a-z] and (.) dot. As most of the domain name contains only lowercase characters we can assume that there will be [a-z] and (.) 27 children for each trie node. 2. When we type www.google.in and google.in the browser takes us to the same page. So, we need to add a domain name into trie for the words after www(.). Similarly while searching for a domain name corresponding IP address remove the www(.) if the user has provided it. This is left as an exercise and for simplicity we have taken care of www. also.

Read full article from How to Implement Forward DNS Look Up Cache? - GeeksforGeeks