What is extended ping on Cisco IOS?

Type ping with no destination in privileged EXEC mode; IOS then prompts for parameters (repeat count, datagram size, timeout, source address/interface, etc.) so you can customize the test.

A plain ping always tests from the router's default source interface, which is sometimes the wrong question. The classic case: a remote network can reach one of your router's interfaces but not another, and a normal ping (sourced from the interface nearest the destination) succeeds and hides the problem. Extended ping lets you set the source address or interface explicitly, so you can prove connectivity as if the packet originated from the far side of the router — exactly the path a real host's traffic would take. The other parameters (repeat count, datagram size, timeout) let you stress-test the path, e.g. sending large packets to expose an MTU or fragmentation issue. You reach it by typing ping with no destination in privileged EXEC mode, then answering the prompts (Enter accepts each default).

How to access:

• Enter privileged EXEC mode
• Type ping without a destination IP address
• IOS will guide you through prompts for various parameters

Customizable Parameters:

• Protocol (IP, IPv6)
• Target IP address
• Repeat count
• Datagram size
• Timeout in seconds
• Extended commands
• Source address or interface
• Type of service
• And more...

Example:

R1# ping
Protocol [ip]:
Target IP address: 192.168.50.1
Repeat count [5]:
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]: y
Source address or interface: 192.168.20.1
...

Note: Pressing Enter accepts the indicated default values. Use ping ipv6 for IPv6 extended ping.

Go deeper:

• Wikipedia — Ping (networking utility) — the parameters (count, size, timeout, source) extended ping lets you tune, and what each affects.