The Traceroute [Destination Ip] Cisco command

Cisco's 'traceroute [destination_ip]' command is a powerful network diagnostic tool used to trace the route taken by packets from a source to a specified destination IP address. It accomplishes this by sending a series of probe packets with increasing Time-to-Live (TTL) values to the destination IP address.

The command is executed from a source device, typically a router or a switch, using the following syntax:

traceroute [destination_ip] [options]

Where:

• [destination_ip] is the IP address of the destination host or network device you want to trace the route to.

• [options] are optional parameters that can be used to customize the behavior of the 'traceroute' command. Some common options include:

  • -m [max_hops]: Specifies the maximum number of hops to traverse before terminating the trace. The default is 30 hops.

  • -w [timeout]: Sets the timeout value in milliseconds for each probe packet. The default timeout is 500 milliseconds.

  • -p [port]: Specifies the port number on the destination host to which the probe packets should be sent. The default is port 33434.

  • -s [source_ip]: Sets the source IP address that the probe packets should be sent from. The default is the IP address of the interface from which the command is executed.

The 'traceroute' command works by sending a series of User Datagram Protocol (UDP) probe packets to the destination IP address with a progressively increasing TTL value. Each probe packet has a TTL value that determines how many network hops it can traverse before being discarded. When a probe packet reaches a router with a TTL value of 0, the router discards the packet and sends an Internet Control Message Protocol (ICMP) Time Exceeded message back to the source device.

By analyzing the ICMP Time Exceeded messages, the 'traceroute' command can determine the path taken by the probe packets to reach the destination IP address. The command displays the IP addresses of the routers or network devices that forward the probe packets, as well as the round-trip time (RTT) for each hop.

The 'traceroute' command is a valuable tool for network administrators to troubleshoot connectivity issues, identify network congestion, and detect routing loops. It can be used on various Cisco equipment, including routers, switches, and firewalls, that run the Cisco IOS operating system.

traceroute [destination_ip] Usage Examples

The syntax for traceroute [destination_ip] command in Cisco is:

traceroute [destination_ip] [additional_parameters]

The following are some examples of the traceroute [destination_ip] command:

• Traceroute to www.google.com with a maximum of 30 hops:

traceroute www.google.com -m 30

• Traceroute to the IP address 8.8.8.8 with a timeout of 5 seconds:

traceroute 8.8.8.8 -w 5

• Traceroute to www.cisco.com with a source IP address of 192.168.1.1:

traceroute www.cisco.com -s 192.168.1.1

• Traceroute to www.microsoft.com using a specific interface (GigabitEthernet0/1):

traceroute www.microsoft.com -i GigabitEthernet0/1

• Traceroute to www.apple.com and resolve hostnames along the path:

traceroute www.apple.com -d

• Traceroute to www.ibm.com and specify the UDP port (443) to use:

traceroute www.ibm.com -p 443

• Traceroute to www.oracle.com and set the maximum transmission unit (MTU) size to 1000 bytes:

traceroute www.oracle.com -mtu 1000

• Traceroute to www.sap.com and specify the type of service (TOS) to use:

traceroute www.sap.com -t 0x18