DHCP issues with DNS

[satya mothukuri]

Hello,

we are using our router as DCHP server for all our branches. Recently  some other company merged with us.

we have having dns issues as the users are not able to resolve the dns ,unless they add fully qualified domain name.

someone suggested to add option 119 in the dhcp pool.

current config looks like this.

ip dhcp pool USERS
network 10.226.129.0 255.255.255.0
domain-name abc.net
dns-server 172.28.224.102 172.28.224.103
default-router 10.226.129.1

Other company domain name is xyz.net.

Please suggest the right solution. Also if i need to add it as option 119, should i use HEX value?

Not sure how to convert abc.net to HEX value.

Please help.

[Jaderson Pessoa]

Well,

I suggest you to configure both domain in suffix dns on machines. You can user a GPO to configure it, look this exemple.

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In Group Policy Management Editor, expand Computer Configuration, expand Policies, expand Administrative Templates, expand Network, and then click DNS Client.
Right-click DNS Suffix Search List, click All Tasks, and then click Edit.
On the DNS Suffix Search List Properties page, select Enabled. In the DNS Suffixes box, type the primary DNS suffix of the disjoint computer, the DNS domain name, and any additional namespaces for other servers with which Exchange may interoperate, such as monitoring servers or servers for third-party applications. Click OK.
In Group Policy Management, expand Group Policy Objects, and then select the policy that you created in Step 4. On the Scope tab, scope the policy so that it applies to only the computers that are disjoint.
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Related link: https://docs.microsoft.com/en-us/exchange/configure-the-dns-suffix-search-list-for-a-disjoint-namespace-exchange-2013-help?redirectedfrom=MSDN

Regards,

[satya mothukuri]

Thanks for your response.

we would like to do this on DHCP server, i mean on Router.

Is there some solution which can do on router?

[Jaderson Pessoa]

I think that on router... you cant do nothing, because they are using different domains. Try configure manually both domains on suffix dns and test... it will work without problem. but for configure on many devices, i suggest to use GPO.

[Jaderson Pessoa]

i found this solution, maybe can work: https://www.perkin.org.uk/posts/serving-multiple-dns-search-domains-in-ios-dhcp.html

[Jaderson Pessoa]

use this link to convert to HEX your domains: https://www.online-toolz.com/tools/text-hex-convertor.php

[paul driver]

Hello

Can you elaborate on what issues your facing regards dns resolution, what users are having the issues - all users of specific users/sites etc...?
Are you using NAT?

Do you have internal and external DNS servers
What is the outcome of a nbtstat -a xxx from a user?