Routing Tables
Last updated
Last updated
Azure Routing Tables (also called Route Tables) define how network traffic is directed within a Virtual Network (VNet) and between VNets or other resources. These tables are used to configure the paths that network traffic takes based on the destination address.
By default, Azure automatically creates a system route table for every VNet, which allows communication within the VNet. This default route table ensures that:
Communication between VMs within the same VNet is allowed.
Traffic destined to other VNets or the internet is routed as needed.
Default Routes: Azure automatically creates default routes for each VNet. This includes:
VNet to VNet communication: Routes traffic between subnets within the VNet.
Internet traffic: Traffic destined for public IP addresses (e.g., to/from the internet) is allowed.
Local route: Allows all traffic within the VNet.
Custom Routes: You can create custom routes to specify how traffic should flow between subnets or out to on-premises networks, virtual appliances, or other connected networks. Custom routes allow for more specific control over the routing decisions.
Destination: The target IP address range.
Next Hop: Defines the destination for traffic (e.g., Virtual Network Gateway, Virtual Appliance, Internet, or None).
Route Table Association: You can associate a route table with a specific subnet or network interface.
Types of Next Hops in Custom Routes:
Virtual Network (VNet): Traffic stays within the VNet and routes to a specific subnet.
Internet: Routes traffic to public IP addresses (for internet-bound traffic).
Virtual Appliance: Routes traffic through a network virtual appliance (e.g., firewall, load balancer).
VNet Peering: Routes traffic between VNets that are connected via VNet peering.
None: Used to disable routing for specific traffic.