With a remote client that uses split tunneling, it is possible for the router to direct DNS queries destined for the corporate DNS server to the pushed DNS server list from the central site if the tunnel is up and to direct DNS queries destined for the ISP DNS server to the outside public interface address if the tunnel is down. Note
Full Answer
What is split DNS and how does it work?
The split DNS infrastructure prevents internal network clients from looping back through the external interface of the ISA Server and lets them connect directly to the publishing servers on the internal network directly via the server’s private, internal network IP address.
Can I have multiple DNS servers for one domain?
You can have Split DNS server and mention the internal domain name for which the DNS server would be the main site DNS server. All other domains will use the ISP DNS server. But this configuration needs to be done on branch locations so that they can decide what DNS traffic should go to the main site.
Does DNS proxy send DNS traffic to the firewall?
With DNS proxy enabled, all DNS traffic will be sent to the firewall. You can have Split DNS server and mention the internal domain name for which the DNS server would be the main site DNS server. All other domains will use the ISP DNS server.
What is a non-split DNS infrastructure?
In a "non-split" DNS infrastructure, you have a single DNS zone for corp.net. Resource records for internally and externally accessible servers are included in the same zone. You publish your own DNS servers so that external network clients can access your published servers. The resource records in the corp.net zone might look like this:
Can a server have multiple DNS?
You can have more than two for a domain but usually three is tops unless you have multiple server farms where you would want to distribute the DNS lookup load. It's a good idea to have at least one of your DNS servers at a separate location.
What is split DNS server?
Split Domain Name System (Split DNS) is a configuration in which two DNS servers (sub-domains) are created for the same domain, one for the internal network and the other for the external, as a means to tighten the security.
What are two common reason for using split DNS systems?
Common reasons for using split DNS systems is to hide internal information from external clients on the Internet or to allow internal networks to resolve DNS on the Internet.
How do I setup a split DNS?
Split DNS – Option 1 (Handy for a single (or few) URLSOn the DNS Server > Windows Key +R > dnsmgmt. msc. ... Right click 'Forward Lookup Zone' > New Zone.Next > Primary Zone > Next > To all DNS servers on domain controllers in this domain > Next > Type in the Zone name > Next > Allow only secure… > Next > Finish.
Should I use split DNS?
A split DNS infrastructure is something you should create whenever you use the same domain name to host resources for both internal and external network clients.
Which setting allows splitting DNS queries?
In the Content Gateway manager:Go to the Configure > Networking > DNS Resolver > Split DNS tab.Enable the Split DNS option.In the Default Domain field, enter the default domain for split DNS requests. ... In the DNS Servers Specification area, click Edit File to open the configuration file editor for the splitdns.More items...
What is split brain DNS Why is it required where is it used?
Split-brain DNS ensures that when users at the office on the local network type in www.mydomain.com, the DNS record returned contains the internal private IP address of the website you've set up, but when users away from the office's local network try to access www.mydomain.com, the DNS record returned contains the ...
What is the difference between authoritative and non authoritative server?
An authoritative answer comes from a nameserver that is considered authoritative for the domain which it's returning a record for (one of the nameservers in the list for the domain you did a lookup on), and a non-authoritative answer comes from anywhere else (a nameserver not in the list for the domain you did a lookup ...
What is a split horizon DNS in Linux?
Split horizon is the ability for a DNS-server to give a different answer to a query based on the source of the query. A common use-case is when using the same DNS-server for internal and external queries.
What is conditional forwarder in DNS?
Conditional forwarders are DNS servers that only forward queries for specific domain names. Instead of forwarding all queries it cannot resolve locally to a forwarder, a conditional forwarder is configured to forward name queries to specific forwarders based on the domain name contained in the query.
What does Edns stand for?
Extension Mechanisms for DNS (EDNS) is a specification for expanding the size of several parameters of the Domain Name System (DNS) protocol which had size restrictions that the Internet engineering community deemed too limited for increasing functionality of the protocol.
What DNS forwarding?
DNS forwarding really helps when a user requests a domain name but the user's DNS server cannot find the matching IP address in its DNS cache, or within its zones of authority. After all, the DNS server is responsible for converting the domain name into the IP address that corresponds to it.
What is a split horizon DNS in Linux?
Split horizon is the ability for a DNS-server to give a different answer to a query based on the source of the query. A common use-case is when using the same DNS-server for internal and external queries.
What is DNS poisoning?
Domain Name System (DNS) poisoning happens when fake information is entered into the cache of a domain name server, resulting in DNS queries producing an incorrect reply, sending users to the wrong website. DNS poisoning also goes by the terms “DNS spoofing” and “DNS cache poisoning.”
What does Edns stand for?
Extension Mechanisms for DNS (EDNS) is a specification for expanding the size of several parameters of the Domain Name System (DNS) protocol which had size restrictions that the Internet engineering community deemed too limited for increasing functionality of the protocol.
What is internal and external DNS?
If you mean Internal as the DNS that may provide you firewall, it is your own DNS that is resolving (or forwarding requests) in your internal LAN. On the other side, the external DNS is the public DNS that resolves the domain request from internet.
What does DNS do to Microsoft?
The DNS server then performs recursion to get the answer for https://www.microsoft.com from the Internet, and caches the response locally.
What happens when a Contoso DNS query is non-authoritative?
If a query for which the Contoso DNS server is non-authoritative is received, such as for https://www.microsoft.com, then the name resolution request is evaluated against the policies on the DNS server.
Why is recursion enabled in Windows Server?
Because the DNS server is also listening to external queries, recursion is enabled for both internal and external clients , making the DNS server an open resolver.
What do you do after you have identified the server interfaces for the external network and internal network?
After you have identified the server interfaces for the external network and internal network and you have created the zone scopes, you must create DNS policies that connect the internal and external zone scopes.
What is the IP address of the second version of the same site?
The second version is the public version of the same site, which is available at the public IP address 65.55.39.10. In the absence of DNS policy, the administrator is required to host these two zones on separate Windows Server DNS servers and manage them separately.
Does DNS have selective recursion?
Now the DNS server is configured with the required DNS policies for either a split-brain name server or a DNS server with selective recursion control enabled for internal clients.
What is split brain DNS?
DNS deployments are split-brain when there are two versions of a single zone, one version for internal users on the organization intranet, and one version for external users – who are, typically, users on the Internet. The topic Use DNS Policy for Split-Brain DNS Deployment explains how you can use DNS policies and zone scopes to deploy ...
Where are DNS policies stored?
DNS policies are stored on the local DNS server. You can easily export DNS policies from one server to another by using the following example Windows PowerShell commands.
What do you do after you have identified the server interfaces for the external network and internal network?
After you have identified the server interfaces for the external network and internal network and you have created the zone scopes, you must create DNS policies that connect the internal and external zone scopes.
What is the IP address of the Internet facing network adapter?
The Internet facing network adapter is configured with a public IP address of 208.84.0.53 for external queries.
Can DNS zones be hosted on the same server?
Using DNS policies these zones can now be hosted on the same DNS server.
Can you create thousands of DNS policies?
You can create thousands of DNS policies according to your traffic management requirements, and all new policies are applied dynamically - without restarting the DNS server - on incoming queries.
Does the zone scope replicate to other servers?
Because you are adding this new zone scope in an Active Directory integrated zone, the zone scope and the records inside it will replicate via Active Directory to other replica servers in the domain.
What is split DNS?
The Split DNS feature enables a Cisco router to respond to Domain Name System (DNS) queries using a specific configuration and associated host table cache that are selected based on certain characteristics of the queries. In a Split DNS environment, multiple DNS databases can be configured on the router, and the Cisco IOS software can be configured to choose one of these DNS name server configurations whenever the router must respond to a DNS query by forwarding or resolving the query.
What is DNS name list?
A DNS name list is a list of hostname pattern-matching rules that could be used as an optional usage restriction on a DNS view list member.
What is DNS view?
A DNS view is a set of parameters that specify how to handle a DNS query. A DNS view defines the following information:
Does Cisco IOS support split DNS?
The DNS forwarding functionality provided by Split DNS to the DNS server subsystem of the Cisco IOS software is available only for DNS packets that are directed to one of the IP addresses of the router that serves as the DNS caching name server. Split DNS does not support processing of packets intercepted at the data link layer (Layer 2) and then redirected to the DNS caching name server.
Can you use hostnames and IP addresses to map?
It is easier to refer to network devices by symbolic names rather than numerical addresses (services such as Telnet can use hostnames or addresses). Hostnames and IP addresses can be associated with one another through static or dynamic means. Manually assigning hostnames-to-address mappings is useful when dynamic mapping is not available.
Can you have more than one DNS view list?
The maximum number of DNS views and view lists supported is not specifically limited but is dependent on the amount of memory on the Cisco router. Configuring a larger number of DNS views and view lists uses more router memory, and configuring a larger number of views in the view lists uses more router processor time. For optimum performance, configure no more views and view list members than needed to support your Split DNS query forwarding or query resolution needs.
What is a split DNS and why would you need it?
A split DNS infrastructure is a solution to the problem of using the same domain name for internally and externally accessible resources. It’s the difference in how internal and external clients access resources that cause the problem.
Why do we need a split DNS?
The split DNS infrastructure prevents internal network clients from looping back through the external interface of the ISA Server and lets them connect directly to the publishing servers on the internal network directly via the server’s private, internal network IP address.
What is a DNS advertiser?
The Basic Split-Split DNS Infrastructure. A DNS Advertiser is a DNS server containing zones for domains you have authority over.
What happens next when ISA server is a client?
What happens next depends on the type of ISA Server client the internal network computer happens to be. If the internal network client is a Web Proxy or Firewall client, the request is successful and the client receives a response from the Web server.
Why does my secure NAT fail?
If the internal network client is a SecureNAT client, the request will fail because the Web server responds directly to the SecureNAT client and not to the ISA Server. The SecureNAT client isn’t expecting a response from the internal network client directly, since it sent its request to the ISA Server, not directly to the internal network Web server. Because of this, the SecureNAT client will drop the packet sent to it by the Web server. I’ll include more details on this in the ISA Server and Beyond Book.
How do internal network clients access DMZ?
Notice the internal network clients access the servers on the DMZ by going through the internal ISA Server. The internal network clients use the actual IP address of the servers on the DMZ segment to access them. The internal ISA Server controls outbound access from the internal network, and that includes access from internal network clients to servers on the DMZ. The reason for this is that even though the IP addresses in the DMZ are private addresses, they are not trusted by internal network clients.
Why do external network clients always get the IP address of the ISA server?
When external network clients resolve the name www.corp.net they always get the external IP address of the ISA Server. That’s exactly what you want because that’s how the external network clients access resources on the internal network. It would do external network clients no good at all to receive the private IP address of the server on the internal network.
What would you need for lan party?
I'm just curious what kind of equipment would you need for smaller lan party. Like if you had 10 people could they just all play on wifi? Or you just buy one unmanaged switch that you connect to router and you are ready? Thanks
I've been looking into buying a smart thermostat but I don't want them to communicate back to HQ. Is there a way to prevent these from phoning home?
I do have an AsusWRT router. I was looking through the settings and it does appear that I can perform blocks on a client level (I click on a client, a window pops-up that has some options, one of which is "Block Internet Access"). Will that suffice? Or will I need to buy something different?
How well do Thunderbolt 3 10GbE adapters work compared to internal PCEe NICs?
Since Thunderbolt 3 has a native PCIe bus, would an 10GbE adapter plugged into it work just as well an an internal NIC? Would there be any speed or latency penalties worth considering?
Running CAT6 drops in the attic
Should cat 6 be buried under insulation or should I attach it to rafters ?
How to build your own internet usage meter?
May I ask for ideas/ suggestions on how to make internet usage metering using raspberry pi? Your response is appreciated.
What IP address is DNS?
Please see the dns server IP (10.13.18.12) I configured in the asa below.
Does VPN use split tunneling?
VPN using split tunneling and DNS. I just set up a firewall for vpn and it has split tunneling enabled. Anything that is going to the network in the standard list does pass thru the VPN. Anything else (ex Internet) not in the acl doesn't pass thru the VPN. That's the purpose of having the split tunneling.
What happens when you have a DNS proxy?
With DNS proxy enabled, all DNS traffic will be sent to the firewall. You can have Split DNS server and mention the internal domain name for which the DNS server would be the main site DNS server. All other domains will use the ISP DNS server.
What is DNS proxy?
The DNS proxy feature provides a transparent mechanism that allows devices to proxy hostname resolution requests on behalf of clients. The proxy can use existing DNS cache, which is either statically configured by you or learned dynamically, to respond to the queries directly.
Does Sonicwall use DNS?
Usually the end computers try to use the primary DNS server configured on their adapter to perform DNS resolutions either internal or external. For the SonicWall to correctly send the DNS traffic for internal and external DNS resolutions, DNS proxy feature can be used.
