--- title: "Meaning & Key Takeaway of: First, to understand why the standard and…" description: "\"“First, to understand why the standard and extended ping results have different effects, consider first the standard ping 172.16.1.51 command on R1, as..." image: "https://sms4smile.com/quotes/i/b4f/wendell-odom-19707_quote_first-to-understand-why-the-standard-and_1231602.jpg" --- # First, to understand why the standard and extended ping… ![“First, to understand why the standard and extended ping results have different effects, consider first the standard ping 172.16.1.51 command on R1, as shown previously in Figure 23-7. As a standard ping command, R1 used its LAN interface IP address (172.16.1.1) as the source of the ICMP Echo. So…” quote by Wendell Odom](https://sms4smile.com/quotes/i/b4f/wendell-odom-19707_quote_first-to-understand-why-the-standard-and_1231602.jpg) [Download](https://sms4smile.com/quotes/i/b4f/wendell-odom-19707_quote_first-to-understand-why-the-standard-and_1231602.jpg) [Open image](https://sms4smile.com/quotes/i/b4f/wendell-odom-19707_quote_first-to-understand-why-the-standard-and_1231602.jpg) > ““First, to understand why the standard and extended ping results have different effects, consider first the standard ping 172.16.1.51 command on R1, as shown previously in Figure 23-7. As a standard ping command, R1 used its LAN interface IP address (172.16.1.1) as the source of the ICMP Echo. So, when the host (A) sent back its ICMP echo reply, host A considered the destination of 172.16.1.1 as being on the same subnet. Host A’s ICMP echo reply message, sent back to 172.16.1.1, would work even if host A did not have a default router setting at all! In comparison, Figure 23-8 shows the difference when using an extended ping on Router R1. An extended ping from local Router R1, using R1’s S0/0/0 IP address of 172.16.4.1 as the source of the ICMP echo request, means that host A’s ICMP echo reply will flow to an address in another subnet, which makes host A use its default router setting.”” [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) ## About This Quote This interpretation was drafted with AI assistance. It is one reading of the quote, not the author's own explanation. The source IP used in a ping determines how the reply is routed; using a LAN interface IP keeps the reply on the same subnet, while using a different interface IP forces the reply to go through the default gateway. **In simple terms:** Ping source IP decides reply path. Key Takeaway Choose appropriate source IP for testing. Themes networking troubleshooting ICMP routing subnetting Mood technical analytical Type educational technical When to use this quote - network diagnostics - router configuration - subnet verification - troubleshooting labs - educational labs Key Concepts IP addressing default gateway packet flow Questions to Reflect On - How does source IP affect reply routing? - When would you prefer extended ping over standard ping? A Different Perspective If the default router is misconfigured, extended ping may still fail despite correct source IP. ★ ★ ★ ★ ★ No ratings yet [Extended Ping](https://sms4smile.com/quotes/about/extended-ping-3810744/) [Icmp Echo](https://sms4smile.com/quotes/about/icmp-echo-369663/) [Ping Command](https://sms4smile.com/quotes/about/ping-command-1279806/) [Ping Results](https://sms4smile.com/quotes/about/ping-results-3810745/) [Standard Ping](https://sms4smile.com/quotes/about/standard-ping-3135421/) ## Related quotes > [“As a quick aside, the example shows a common and normal behavior with ping commands: the first ping command shows one failure to start,…](https://sms4smile.com/quotes/wendell-odom/as-a-quick-aside-the-example-shows-a-common-and-normal-behavior-with/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“Testing LAN Neighbors with Standard Ping”](https://sms4smile.com/quotes/wendell-odom/testing-lan-neighbors-with-standard-ping/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“Host B can send ICMP echo reply messages to R1’s 172.16.4.1 IP address (hosts send echo reply messages to the IP address from which…](https://sms4smile.com/quotes/wendell-odom/host-b-can-send-icmp-echo-reply-messages-to-r1-s-172-16-4-1-ip/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“First, take a moment to review the output of the first IOS ping command. By default, the Cisco IOS ping command sends five echo…](https://sms4smile.com/quotes/wendell-odom/first-take-a-moment-to-review-the-output-of-the-first-ios-ping/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“Ping Command Basics The ping command tests connectivity by sending packets to an IP address, expecting the device at that address to send packets…](https://sms4smile.com/quotes/wendell-odom/ping-command-basics-the-ping-command-tests-connectivity-by-sending/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“Problem Isolation Using the ping Command Someone sends you an email or text, or a phone message, asking you to look into a user’s…](https://sms4smile.com/quotes/wendell-odom/problem-isolation-using-the-ping-command-someone-sends-you-an-email/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) ## More by Wendell Odom > [“Host B can send ICMP echo reply messages to R1’s 172.16.4.1 IP address (hosts send echo reply messages to the IP address from which…](https://sms4smile.com/quotes/wendell-odom/host-b-can-send-icmp-echo-reply-messages-to-r1-s-172-16-4-1-ip/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“NTP Using a Loopback Interface for Better Availability An NTP server will accept NTP messages arriving to any of its IPv4 addresses by default.…](https://sms4smile.com/quotes/wendell-odom/ntp-using-a-loopback-interface-for-better-availability-an-ntp-server/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“Storing Log Messages for Later Review With logging to the console and to terminals, an event happens, IOS sends the messages to the console…](https://sms4smile.com/quotes/wendell-odom/storing-log-messages-for-later-review-with-logging-to-the-console-and/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“Sending Messages in Real Time to Current Users Cisco IOS running on a device at least tries to allow current users to see log…](https://sms4smile.com/quotes/wendell-odom/sending-messages-in-real-time-to-current-users-cisco-ios-running-on-a/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“System Message Logging (Syslog) It is amazing just how helpful Cisco devices try to be to their administrators. 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However, that default configuration is not enough to allow the user to see the log messages.…](https://sms4smile.com/quotes/wendell-odom/sending-of-log-messages-to-all-logged-users-however-that-default/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“First, note that the example configures the same message level at the console and for terminal monitoring (level 7, or debug), and the same…](https://sms4smile.com/quotes/wendell-odom/first-note-that-the-example-configures-the-same-message-level-at-the/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“root cause of the problem may be happening, further isolating the problem. This section begins with a brief explanation of how ping works. It…](https://sms4smile.com/quotes/wendell-odom/root-cause-of-the-problem-may-be-happening-further-isolating-the/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“For instance, consider the topology in Figure 33-6, with Router R4 on the right acting as NTP server and the other routers acting as…](https://sms4smile.com/quotes/wendell-odom/for-instance-consider-the-topology-in-figure-33-6-with-router-r4-on/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“If the ping works, it confirms the following, which rules out some potential issues: The host with address 172.16.1.51 replied. The LAN can pass…](https://sms4smile.com/quotes/wendell-odom/if-the-ping-works-it-confirms-the-following-which-rules-out-some/) [Wendell Odom](https://sms4smile.com/quotes/author/wendell-odom/) > [“Log Message Format IOS defines the format of log messages. 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