Network Watcher

In the Ultra Transcenders books

AZ-305AZ-104AZ-700

Each book explains Network Watcher in context, with comparison tables and the common traps.

Terms in this definition

• Next hop

  For a destination you specify, returns the route table in use along with the next hop's type and IP. Only routing is checked.

• IP flow verify

  Network Watcher tool that tests a packet and reports whether it would be let through or dropped, naming the deciding NSG rule.

• Packet capture

  Network Watcher feature that records a VM's traffic, filtered by 5-tuple and bounded by a time limit (18,000 seconds, or 5 hours, by default). It depends on the Network Watcher Agent extension.

• Connection Monitor

  Continuously probes network paths from sources to destinations in Network Watcher. Each monitor accepts source VMs only from its own region, so multiple source regions mean multiple monitors.

• Flow

  The unit of work inside a Lakeflow pipeline that takes data from a source, transforms it and lands it in a destination like a streaming table. Streaming flows either append or update, and CREATE FLOW lets you declare a flow apart from the table it feeds.

Related terms

• 5-tuple

  The five values that identify a flow: protocol plus the source and destination IP addresses and ports. Azure Load Balancer hashes them by default to spread traffic, and IP flow verify in Network Watcher takes them as its input.

• Connection troubleshoot

  One-time Network Watcher check from a VM to another VM, an FQDN, a URI or an IP and port, reporting whether it is reachable, the latency and which hop (route or NSG) breaks it.

• Effective security rules

  Network Watcher feature showing the merged subnet and NIC NSG rules that apply to a network interface; it does not test any traffic.

• Microsoft.Network

  Namespace of the Azure resource provider for networking, covering VNets, NSGs, Network Watcher and more. Network Contributor is granted its actions.

• Topology

  A Network Watcher view diagramming the resources in a VNet and how they relate. Traffic and packets are not shown.

• Traffic Analytics

  Using NSG or VNet flow logs, this Network Watcher feature reveals traffic patterns and top talkers. Rule evaluation is outside its scope.

• Virtual network flow logs

  Replacing NSG flow logs, these Network Watcher logs are switched on at the VNet and capture traffic per flow rather than per packet, storing it in a storage account for Traffic Analytics to use.

• VPN troubleshoot

  Diagnoses a route-based VPN gateway or connection on demand from Network Watcher, storing logs in a storage account. Alerts aren't possible, and ExpressRoute isn't supported.