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When using Webex with the DNSFilter Windows Roaming Client, users may experience connectivity failures. This occurs because Webex sometimes relies on older NAPTR records that the Roaming Client cannot process correctly.

Create an NRPT Rule for the Webex domains to resolve the issue. This rule bypasses the Windows agent so the Webex traffic successfully connects through a public server.

Identify the Webex FQDN

The exact URL for the Webex NRPT rule may vary depending on the ISP used for SIP services. 

1. Attempt to replicate the issue in Webex
2. Generate diagnostics:
   1. Download the Windows Roaming Client log files
   2. Navigate to the logs directory: C:\Program Files\DNSFilter Agent\logs or C:\Program Files\DNS Agent\logs
   3. Open the most recent dns-query.txt or agent-operations.txt logs
3. Search for a NAPTR query

Example log entry:

DEBUG DnsProxy - [14574] [IPv4] - Question name: vic-all.business.connect.telstra.com., Question type: Naptr, Class: INet

In this example, Webex is using vic-all.business.connect.telstra.com

Create an NRPT Rule

Use a PowerShell script to bypass the Roaming Client for the impacted Webex domain and force resolution through an alternate DNS server.

1. Open PowerShell as Administrator

2. Run the following script (update $DnsServer  and $Namespace to match the destination DNS server and NAPTR from above):

   $Namespace   = "vic-all.business.connect.telstra.com"      
   $DnsServer   = "8.8.8.8"            
   $DisplayName = "DNSFilter /w Webex"
   
   # Check if rule exists
   $existingRule = Get-DnsClientNrptRule | Where-Object { $_.Namespace -eq $Namespace }
   if ($existingRule) {
     Write-Host "NRPT rule for $Namespace already exists. Removing before adding..."
     Remove-DnsClientNrptRule -Namespace $Namespace -Force
   }
   
   # Add the NRPT rule
   Add-DnsClientNrptRule `
     -Namespace $Namespace `
     -NameServers $DnsServer `
     -DisplayName $DisplayName
   
   Write-Host "NRPT rule added for $Namespace using DNS server $DnsServer"

3. Confirm the rule was added: Get-DnsClientNrptRule

The Webex traffic should bypass the Roaming Client and connect successfully.