Azure Networking Cost Optimization & Monitoring
Azure networking is powerful — but can get expensive if you’re not careful.
This post covers:
- What costs the most in Azure networking?
- How to reduce cost without compromising security
- Tools to monitor and alert for network health
What Costs the Most?
| Resource | Cost Impact |
|---|---|
| Azure Firewall | $$$ — Pay per deployment + GB used |
| ExpressRoute | $$$ — Monthly base + bandwidth |
| Data Transfer | Charges for traffic between regions or zones |
| VPN Gateway | Based on SKU and time |
| Peering | Inbound = Free, Outbound = $$$ |
| Public IP | Basic = Free, Standard = Billable |
Cost Optimization Tips
Use NAT Gateway Instead of Load Balancer SNAT
- Avoid port exhaustion
- More scalable for outbound traffic
- Predictable IP and cost
Consolidate Firewalls in Hub
- One Azure Firewall in the Hub VNet
- Route all traffic through it
- Use UDRs and ASGs to enforce control
Avoid Cross-Region Traffic
- Peering across regions = paid outbound
- Keep apps and databases in same region when possible
Use Azure Cost Management
- Enable tags on VNet, Firewall, NAT Gateway
- Group by project/team/app
- Set up budgets and alerts
Monitoring Tools
| Tool | Use For |
|---|---|
| Network Watcher | Packet capture, NSG flow logs |
| Azure Monitor | Metrics for Firewall, VPN, Gateway |
| Log Analytics | Query NSG and Firewall logs |
| Connection Monitor | End-to-end checks (latency, loss) |
Monitor These Metrics
- Firewall throughput
- NAT Gateway SNAT ports used
- VPN Tunnel status (S2S, P2S)
- Inbound/outbound bytes per VNet
- Number of dropped packets (NSG)
Set Alerts (Examples)
- Alert if VPN Gateway is down
- Alert if Azure Firewall hits 80% throughput
- Alert on unexpected data transfer spikes
Final Tip
Secure, scalable Azure networking is possible without breaking the bank.
But it requires:Planning IP space
Designing with hub-spoke
Monitoring everything!
Learn More
Thanks for following the Azure Networking Series —
Let’s build better cloud networks, the KasdevTech way!
– Kasi @ KasdevTech or LinkedIn