Forum Discussion
routing table
Hello,
I have a virtual network with 192.168.0.0/24. In the virtual network is a firewall with 192.168.0.5.
Now I want to route any outgoing traffic on the virtual network through the firewall.
If I create a rule 0.0.0.0/0 to 192.168.0.5 - The internal devices can not reach each other. What is the best way to set the routing rules here?
Greetings and thanks
Stefan
1 Reply
Take this:
- Use a User-Defined Route (UDR)
- Create a route table with:
- Destination: 0.0.0.0/0
- Next hop type: Virtual appliance
- Next hop IP: 192.168.0.5 (your firewall)
- Associate the Route Table with Subnets
- Apply the route table to application subnets, not the firewall subnet
- This ensures only outbound traffic from those subnets is routed through the firewall
- Preserve Internal Traffic
- Internal traffic (e.g., between VMs in the same subnet or VNet) uses system routes
- To avoid breaking it:
- Do not override internal IP ranges like 192.168.0.0/24 in your custom route table
- Let Azure’s default routing handle intra-subnet communication
- Firewall Configuration
- Ensure the firewall can:
- Route traffic back to internal subnets
- Handle NAT or SNAT if needed for outbound internet access
- Allow return traffic from the internet
