Overview of the Inbuilt Traffic Generator
Feature Name |
Release Information |
Description |
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Inbuilt Traffic Generator for Network Diagnostics |
Release 24.2.11 |
By introducing an inbuilt traffic generator in the Network Processing Unit (NPU) of line cards (LCs) of distributed systems and route processors (RPs) of fixed routers, we've ensured that the traffic generator is always available for network diagnostics. You also don't face compatibility issues because the traffic generator is inbuilt and easy to maintain. Previously, connecting an external traffic generator was necessary to inject packets to test networks. This feature introduces these changes: CLI:
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The inbuilt traffic generator is implemented within the Cisco Silicon One Application-Specific Integrated Circuit (ASIC), which is the Network Processing Unit (NPU) of linecards and fixed routers of the Cisco 8000 Series Routers.
![]() Caution |
Don’t run the inbuilt traffic generator on a live network unless you are fully aware of the impact of packets injected. Injecting packets into a live network may result in network outages. |
The inbuilt traffic generator works in three modes:
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Ingress mode: In this mode, the traffic generator injects ingress packets to an interface as if received from an upstream router. The NPU processes these packets normally and sends them to the egress interface based on looking up the Forwarding Information Base (FIB) programmed in the NPU. The NPU may encapsulate the packet and rewrite the packet headers before sending the packet out of the egress interface.
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Egress mode: In this mode, the traffic generator injects packets directly to an egress interface. If the egress interface is on another line card, the router sends the injected packet through the fabric and to another NPU where the egress interface is located. The router sends these packets as-is from the egress interface. So, you must be careful to formulate these packets with a valid Layer 2 header so that the downstream routers can process the packets.
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Raw mode: This mode is an advanced traffic generator mode where the user has full control. In this mode, the user can control the packets within the NPU by defining the inject headers of the packet.
Caution
Improper use of raw mode could cause unexpected behavior, such as NPU lock-up. It is recommended that only Cisco engineers create traffic generator instances in raw mode.