DNS Configuration Templates
5.1 DNS Architecture Overview
5.1.1 Webex DNS Requirements Summary
| Service |
FQDN Pattern |
Resolution |
Purpose |
| Webex Calling |
*.webex.com |
Public DNS |
Core calling services |
| Webex Edge |
*.ucmgmt.cisco.com |
Public DNS |
Device management |
| Local Gateway |
*.ciscowebex.com |
Public DNS |
LGW registration |
| Media Nodes |
*.wbx2.com |
Public DNS |
Voice/video media |
| Control Hub |
admin.webex.com |
Public DNS |
Administration |
5.1.2 DNS Resolution Architecture
+-----------------------------------------------------------------+
| DNS RESOLUTION - ABHAVTECH |
+-----------------------------------------------------------------+
| |
| INTERNAL CLIENTS EXTERNAL RESOLUTION |
| |
| +----------+ +----------+ +----------+ +----------+ |
| | Webex App|--->| Internal |--->| Forwarder|--->| Public | |
| | / Phone | | DNS | | (SD-WAN) | | DNS | |
| +----------+ +----------+ +----------+ +----------+ |
| | | |
| | Split DNS | |
| v v |
| +----------+ +----------+ |
| | Internal | | Webex | |
| | Zones | | Cloud | |
| +----------+ +----------+ |
| |
| KEY REQUIREMENT: No DNS interception for *.webex.com |
| |
+-----------------------------------------------------------------+
5.1.3 Critical DNS Rules
| Rule |
Requirement |
Validation |
| No proxy |
Webex domains must bypass web proxy |
nslookup webex.com returns public IP |
| No interception |
SSL inspection disabled for Webex |
Certificate = DigiCert (not internal CA) |
| Low TTL respect |
Honor TTL values (failover) |
DNS cache TTL <= 300s |
| IPv4 preferred |
Dual-stack: prefer A over AAAA |
Client config or DNS policy |
5.2 India DNS Configuration
5.2.1 India Internal DNS Servers
| Site |
DNS Server |
IP Address |
Forwarder |
| Mumbai HQ |
dc-mum-01.abhavtech.com |
10.1.10.5 |
8.8.8.8, 8.8.4.4 |
| Mumbai HQ |
dc-mum-02.abhavtech.com |
10.1.10.6 |
8.8.8.8, 8.8.4.4 |
| Chennai |
dc-che-01.abhavtech.com |
10.2.10.5 |
10.1.10.5 (via SD-WAN) |
| Bangalore |
dc-blr-01.abhavtech.com |
10.3.10.5 |
10.1.10.5 (via SD-WAN) |
5.2.2 India LGW DNS Records
Internal DNS Zone: abhavtech.com
; Local Gateway A Records
lgw-mum-01.abhavtech.com. IN A 10.1.50.10
lgw-mum-02.abhavtech.com. IN A 10.1.50.11
lgw-che-01.abhavtech.com. IN A 10.2.50.10
lgw-blr-01.abhavtech.com. IN A 10.3.50.10
lgw-del-01.abhavtech.com. IN A 10.4.50.10
lgw-noi-01.abhavtech.com. IN A 10.5.50.10
lgw-hyd-01.abhavtech.com. IN A 10.7.50.10
; SRV Records (if using SRV-based routing)
_sips._tcp.lgw-mum.abhavtech.com. IN SRV 10 10 5061 lgw-mum-01.abhavtech.com.
_sips._tcp.lgw-mum.abhavtech.com. IN SRV 20 10 5061 lgw-mum-02.abhavtech.com.
5.2.3 Windows DNS Configuration (Mumbai)
# Add Conditional Forwarder for Webex (bypass internal resolution)
Add-DnsServerConditionalForwarderZone -Name "webex.com" -MasterServers 8.8.8.8,8.8.4.4
Add-DnsServerConditionalForwarderZone -Name "wbx2.com" -MasterServers 8.8.8.8,8.8.4.4
Add-DnsServerConditionalForwarderZone -Name "ciscospark.com" -MasterServers 8.8.8.8,8.8.4.4
# Verify
Get-DnsServerZone | Where-Object {$_.ZoneType -eq 'Forwarder'}
5.3 EMEA DNS Configuration
5.3.1 EMEA DNS Servers
| Site |
DNS Server |
IP Address |
Forwarder |
| London |
dc-lon-01.abhavtech.com |
10.20.10.5 |
8.8.8.8, 1.1.1.1 |
| Frankfurt |
dc-fra-01.abhavtech.com |
10.21.10.5 |
8.8.8.8, 1.1.1.1 |
5.3.2 EMEA-Specific DNS Considerations
| Requirement |
Configuration |
| GDPR-compliant DNS |
Use EU-based public DNS or internal only |
| UK data path |
London clients resolve via UK DNS first |
| No LGW records |
CCPP used - no internal gateway DNS needed |
5.4 Americas DNS Configuration
5.4.1 Americas DNS Servers
| Site |
DNS Server |
IP Address |
Forwarder |
| New Jersey |
dc-nj-01.abhavtech.com |
10.30.10.5 |
8.8.8.8, 8.8.4.4 |
| Dallas |
dc-dal-01.abhavtech.com |
10.31.10.5 |
10.30.10.5 |
5.4.2 E911 Location Service DNS
; RedSky/Intrado E911 service endpoints (if self-hosted LIS)
e911-lis.abhavtech.com. IN A 10.30.50.20