TopicIT Networking →
⌚ About 2 min read
Observer the different network jumps borrowed by packages to a destination.
Avant de commencer : adaptez toujours les commandes et manipulations à votre environnement. Sur un système de production, prévoyez une backup ou un retour arrière lorsque l’action peut modifier la configuration.
Étapes à suivre
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1
Open a terminal.
Run Windows Terminal.
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2
Run tracet.
Enter tracet followed by the name DNS or the IP address.
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3
Watching the jumps.
Each line corresponds to a step of the network path.
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4
Compare with the routing table.
Use print road to control local roads.
Commands utiles
tracer 8.8.8.
road print.
À retenir
- Asterisks in tracer do not necessarily mean that equipment is out of order: some routers filter ICMP.
- The first jump is usually the local gateway.
Windows routing: read the route actually selected
Technical checkpoints
- Windows selects the most specific prefix first, then the metric; merely having a route does not mean it will be used.
- Get-NetRoute and Get-NetIPInterface link routes, interfaces and metrics.
- tracert shows hops that answer ICMP; some routers do not reply even when application traffic is not blocked.
Route to a target
Compare the default route, more specific routes and metrics before blaming WAN/VPN.
Get-NetRoute -AddressFamily IPv4 | Sort-Object DestinationPrefix
tracert 10.20.30.40Topic-specific pitfalls
- Adding a static route as a test can hide the real cause and may accidentally remain persistent.
- VPN clients can inject more specific routes or change metrics.
How to validate
- The most specific route to the target uses the expected interface and gateway.
- The return path is also checked when traffic is asymmetric or filtered.