Att fiber DNS server?

We've just switched from cox internet to att today however we have a sonicwall tz300 which has the cox dns servers. Would I just simply input the att fiber dns server any will be up and running?

You should probably quit using the Cox DNS servers, though you can get by with them for a while.  AT&T's DNS servers would be Primary 68.94.156.1; Secondary 68.94.157.1). You could also use Cloudflare (1.1.1.1, 1.0.0.1) or Google's (8.8.8.8, 8.8.4.4) public DNS servers.   You could also use one and another's primary as your backup.

Also do I need to enable ip pass-through and select the firewalls MAC address?

You probably should.  This will keep you from having double-NAT.

Lastly, since we have a firewall, do we also need static ip addresses? 

You do not need static ip addresses "because you have a firewall."  You may need static ip addresses for another reason.  Do you host any services (FTP site, etc.) in your office that have to be reached from outside?

Hi @Thadds, we understand your concern. Let's get the help you need.

We recommend that you could either do IP passthrough or port forwarding when you are having AT&T gateway with sonic firewall where in the ippasthrough gives you direct access to the public IP and port forwarding gives you  selectively exposes to specific services.

Please choose the method that aligns with your network requirements and expertise.

Let us know how it goes.

Thank you for contacting AT&T Community Forums.

Jasmine, AT&T Community Specialist

@ATTHelp @JefferMC thank you, I've enabled IP passthrough and selected DHCPS-fixed option, selected the MAC for the sonic firewall, but still have no internet connection on any of the computers. I've also set the DNS servers on the firewall to 68.94.156.8/68.94.157.8 and still no luck. Do I need to enable or disable DHCPv4 server on the firewall? Do I need to somehow disable static settings / server lease scopes on the firewall? The tech who installed the service couldn't help :(

After doing the IP Passthrough you have to get the Sonic Firewall to re-request an IP (assuming that it's configured to Dynamically pull an IP via DHCP vs it being statically configured...), so:

a) check that the Sonic Firewall is configured for DHCP on the WAN interface.

b) If there's an obvious way to tell it to renew its IP, do so, otherwise, turn it off for 5 minutes, then turn it back on

c) Check to ensure that the Sonic Firewall's WAN IP address is now the same public IP as the AT&T Gateway.

Hi @Thadds

We understand your concern. The Community Forums are a public support option where other users, and AT&T, will try and assist with high level support needs. This means we won’t be able to look into account specific concerns. To get the help you need for your unique issue, please review our Contact Us page - https://www.att.com/support/contact-us/, and choose the best option to reach out to us. You can call, chat, or reach out via social media, and we can review your specific issue and provide you support. If you feel your issue isn’t account specific, and can be answered generally, please let us know, and we’ll be happy to help.

Thank you for contacting AT&T Community Forums,
Maria, AT&T Community Specialist.