Using the traceroute Command

Chapter 6 Troubleshooting the Cisco IOS XR Software

Basic Troubleshooting Commands

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Use the traceroute command in EXEC mode to discover the routes that packets take when traveling to their destination. Enter a hostname or an IP address as an argument to this command.

This command works by taking advantage of the error messages generated by routers when a datagram exceeds its time-to-live (TTL) value.

The traceroute command starts by sending probe datagrams with a TTL value of 1, causing the first router to discard the probe datagram and send back an error message. The traceroute command sends several probes at each TTL level and displays the round-trip time for each.

The traceroute command sends one probe at a time. Each outgoing packet may result in one or two error messages. A time exceeded error message indicates that an intermediate router has seen and discarded the probe. A destination unreachable error message indicates that the destination node has received the probe and discarded it because it could not deliver the packet. If the timer times out before a response comes in, the traceroute command prints an asterisk (*).

The traceroute command terminates when the destination responds, the maximum TTL is exceeded, or the user interrupts the trace with the escape sequence.

Examples

In the following example, the route for an IP address appears:

RP/0/RSP0/CPU0:router# traceroute 10.233.233.233

Type escape sequence to abort.

Tracing the route to 10.233.233.233

1	172.25.0.2 11 msec 2 msec	1 msec
2	192.255.254.254 1 msec *	2 msec

Using debug Commands

Debug commands are used to diagnose and resolve network problems. Use debug commands to troubleshoot specific problems or during troubleshooting sessions.

Use debug commands to turn on or off debugging for a specific service or subsystem. When debugging is turned on for a service, a debug message is generated each time the debugging code section is entered. The following sections provide information on debugging:

•Viewing a List of Debug Features, page 6-4

•Enabling Debugging for a Feature, page 6-4

•Viewing Debugging Status, page 6-5

•Disabling Debugging for All Services Started at the Active Terminal Session, page 6-5

•Disabling Debugging for All Services Started at All Terminal Sessions, page 6-6

Caution Debug commands can generate a very large amount of output and can render the system unusable. Use debug to troubleshoot specific problems or during specific troubleshooting sessions on systems that are not in production.

Cisco ASR 9000 Series Aggregation Services Router Getting Started Guide

	OL-17502-01	6-3

A9KMOD80TR, A9K24X10GETR, ASR 9000 specifications

Cisco Systems has long been a leader in networking technology, providing cutting-edge solutions for service providers and enterprise organizations alike. Among their standout products is the Cisco ASR 9000 Series Aggregation Services Routers, notably the A9K24X10GETR and the A9KMOD80TR models. These routers are engineered to deliver unmatched performance, scalability, and versatility for networks that require high bandwidth and low latency.

The Cisco ASR 9000 Series is built for the needs of today's complex service provider and enterprise networks. A significant feature of the A9K24X10GETR is its 24-port 10-Gigabit Ethernet module. This functionality allows for high-density connectivity, making it ideal for aggregating numerous connections to different parts of a network while maintaining optimal performance. Whether used for Internet service providers delivering high-speed connectivity or for enterprises looking to connect multiple branches, the A9K24X10GETR provides robust and reliable data transmission.

Further enhancing the capabilities of the ASR 9000 is the A9KMOD80TR module, which supports an extensive range of services. This module is designed to run a variety of technologies, including Layer 2 and Layer 3 services, MPLS (Multiprotocol Label Switching), and IPv6. Its ability to integrate seamlessly into existing infrastructures while providing the advanced features customers demand makes it an invaluable asset for network engineering teams.

Another cutting-edge technology present in the ASR 9000 Series is its support for eBGP (External Border Gateway Protocol), which plays a critical role in managing traffic across multiple networks. The routers are equipped with advanced telemetry features, empowering operators with real-time insights into network performance and health. Additionally, they come with integrated security features that protect against DDoS threats and other vulnerabilities.

In summary, Cisco's ASR 9000 Series, particularly the A9K24X10GETR and A9KMOD80TR, combines high-density connections, extensive service support, and advanced security and telemetry capabilities. These routers are perfect for demanding environments where reliable performance and adaptability are crucial. With their focus on innovation and performance, Cisco continues to shape the future of networking technology.

Cisco Systems A9KMOD80TR, ASR 9000 manual Using the traceroute Command, Using debug Commands

Models: A9KMOD80TR A9K24X10GETR ASR 9000

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