Local DNS records provides all the relevant information to the client from the track and avoid security risk for internal services.Local DNS server have a set of separate DNS records to keep the track.Attackers from public network or outside world cannot be able to get the details of internal services as to attack the servers from Untrust Zone.Resolves to A record of to internal Server IP address 10.10.10.22. Similarly, if internal users connect to ftp-server on port 21, CNAME of ftp. Here, CNAME of and request forwards to 10.10.10.33 When internal users try to access the website on port 80, they will connect to the Internal Zone server. However, when we configure Internal zone database to answer internal queries If traffic on port FTP, SMTP (email) are used by external users then traffic redirects to the same internal server however redirection ports are changed. Whenever external users access from outside, traffic gets NAT IP address (external zone IP address) from firewall. We can configure External Zone database like this: As discussed before, one zone handles internal domain requests and the other zone can answer external domain queries from the outside world. To implement Split-DNS in any network we would require two different zones for the same Domain. Now local DNS will have the necessary information to refer the client directly to the web server.ĭNS admin must include all records that are found on the external DNS zone in internal/Local DNS server. Next time the INTRANET client opens the URL in the browser and contacts the local DNS server. In this scenario for the INTRANET Client to be able to access the webserver Īdmin must have added a record called and map that to the IP address of the server on the internet. In split DNS design, records that are sorted on the external DNS zone must also be included in the Internal DNS.If the record zone, DNS resolution will fail for the INTRANET client.Therefore, it will respond back to the Intranet client without proceeding any other resolution.Now internal or Local DNS server is authoritative for zone.However, when it comes to the INTRANET client, if the client opens the browser to connect with, request goes out to the local DNS server.So, in this scenario, for the internet clients nothing has been changed.zone will be available in both internal and external DNS server.First action is to host within the Local DNS server.Split DNS or Split Domain Name System Workingįurther when Split Domain Name System is introduced in the Local DNS server the traffic will works as below: So, this is how a normal DNS server works for Internal and external hosts. From where local Client can connect with web server directly.Local DNS server respond back to the Local Intranet Client.Eventually the request will make its own way to the DNS server holding a on the Internet that server respond back with the IP address of the web server back to the local DNS server inside the Internet Zone. Forward the traffic to another DNS server, possibly DNS server which is used by ISP.The Local server trying to locate the DNS server by its routes.Since the Local DNS server is not Authoritative for the.Session communicates with the Company’s local DNS server.On the INTRANET (not Internet) client when opens browser and type then: In more detail we can understand the process as follows: Now traffic returns to the DNS server from where local Intranet users can get the DNS resolution and are able to open the URL. ISP DNS/Internet Cloud to Web Server: Query reaches to Public hosted server and reply to firewall.Firewall to Internet Cloud: Firewall trying to reach Internet cloud and communicate with Global/ ISP DNS to connect with Public hosted server.Local DNS Server : initiates connection towards Internet Firewall.Intranet user (Internal User) : Internal user initiates connection to website which is hosted on the Internet.In the above image Normal DNS performs following steps: And web page served back to the Internet User.Internal client will then make a direct connection to that web server.DNS servers connect with internet client with the IP address of the web server which holds the website and check the IP address assigned to the URL.External DNS server has hosted the zone.Internet Client will go through the DNS process and hits the External DNS server.When an Internet client open a Web-browser and type However, DNS works to resolve names to IPs. Before understanding the Split Domain Name System, let’s discuss how normal DNS resolution works for Internet traffic.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |