# Do you have to know an IP to be able to ping it? **URL:** \ **Category:** Factual Questions\ **Created:** [September 20, 2006, 6:07pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446 "2006-09-20T18:07:32Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![DeadlyAccurate](https://avatars.discourse-cdn.com/v4/letter/d/ac91a4/32.png) [@DeadlyAccurate](https://boards.straightdope.com/u/DeadlyAccurate)\ **Post date:** [September 20, 2006, 6:07pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/1 "2006-09-20T18:07:32Z")
I have a character in my book who was hacking into someone’s data lines when his security programs started warning him that he’d gotten caught. Hm, not sure if that’s making sense. Maybe if I post the section in question: > [@](#): > > ``` > “They almost found me,” he gasped. “They were running traces on all data transfers and requests, and all of a sudden my security programs started warning me that someone was trying to ping my IP.” > Was he speaking English? “What’s that mean exactly?” > “Don’t you get it?” he yelled. “It means they had to know my IP to be able to ping it. God, I’ve got so much work to do.” He started mumbling something about routers and ports and firewalls, but I didn’t ask for clarification. He might have tried to explain. > > ``` In other words, does this section make sense, or would you laugh yourself out of the room if you’d read it in a book? ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [September 20, 2006, 6:12pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/2 "2006-09-20T18:12:15Z")
You need to know the IP address to ping it. I wouldn’t worry about getting the computer stuff correct in your book. Nobody else gets computer stuff correct. If you did get it correct most of the reading audience would think it boring and lame. ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [September 20, 2006, 6:17pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/3 "2006-09-20T18:17:23Z")
I could ping any recognize name. As an example, ping [www.google.com](http://www.google.com) DNS handles the conversion from name to IP address. Additionally many firewalls detect, determine all probes against them with I believe a trace routine. Early on before home firewalls were common I had an PC that I used to share internet and run BLACKICE. BlackIce would report all the probes against my systems. A good hacker would not probe someones dataline without some intermediaries to prevent proper tracing. I guess I am saying your quoted exchange does not make much sense to me. Jim ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [September 20, 2006, 6:19pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/4 "2006-09-20T18:19:14Z")
[QUOTE=gazpacho] You need to know the IP address to ping it. I wouldn’t worry about getting the computer stuff correct in your book. Nobody else gets computer stuff correct. If you did get it correct most of the reading audience would think it boring and lame. [/QUOTE] First sentence is just not true, the second one is reasonable and I think good advice. Jim ---
**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\ **Post date:** [September 20, 2006, 6:22pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/5 "2006-09-20T18:22:28Z")
[Disclaimer - I’m no expert, but have been in the company of experts for at least a decade] The “trying” bit sounds suspect me. They either ping it or they don’t. The only way you know it’s happening is when the ping packet/s arrive, at which point you’ve already been pinged. If you’ve disabled ping response, that’s fine, but you’ve still been pinged. Also, it’s unlikely they’d say “ping my IP address”; they’d probably say “ping my server”, “ping my computer”, or “ping me”. ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [September 20, 2006, 6:23pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/6 "2006-09-20T18:23:01Z")
[QUOTE=What Exit?] First sentence is just not true, the second one is reasonable and I think good advice. Jim [/QUOTE] Sure it is. How else is the ping addressed if not with IP address? ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [September 20, 2006, 6:25pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/7 "2006-09-20T18:25:33Z")
[QUOTE=gazpacho] Sure it is. How else is the ping addressed if not with IP address? [/QUOTE] Already explained, Ping the DNS name. example Ping [www.google.com](http://www.google.com) and discover that 64.233.161.99 is 15ms away. 😉 Jim ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [September 20, 2006, 6:31pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/8 "2006-09-20T18:31:57Z")
I just don’t see how knowing the DNS name is not really the same as knowing the IP address. The computer that is sending the ping packet knows the IP address. It is not like once you know the DNS name that the IP address can somehow be kept secret. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [September 20, 2006, 6:34pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/9 "2006-09-20T18:34:58Z")
[QUOTE=What Exit?] Already explained, Ping the DNS name. [/QUOTE] So the bad guys are pinging [goodguy.com](http://goodguy.com)? ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [September 20, 2006, 6:38pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/10 "2006-09-20T18:38:22Z")
[QUOTE=gazpacho] I just don’t see how knowing the DNS name is not really the same as knowing the IP address. The computer that is sending the ping packet knows the IP address. It is not like once you know the DNS name that the IP address can somehow be kept secret. [/QUOTE] You are splitting hairs I think. You said “You need to know the IP address to ping it.” I was simply correcting you. I do not need to know the IP address of the Yankees, I simply ping [www.yankees.com](http://www.yankees.com) and I learn their IP address. Your statement was not correct and I was letting you know it was. I use this quite often in the office as I am more likely to know a Computer’s name then address. Jim ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [September 20, 2006, 6:43pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/11 "2006-09-20T18:43:13Z")
[QUOTE=carnivorousplant] So the bad guys are pinging [goodguy.com](http://goodguy.com)? [/QUOTE] The Op solicited a simple Computer Geek answer, a computer geek has provided one. There are many ways to determine an IP address. Get a network Expert into the thread and he will bore you to tears with the ways. The simplest method is a good firewall appliance that logs and traces back all probes. The Software has been around for a long time and available to mid-level Computer geeks like me since the late 90s. Jim ---
**Author:** ![gazpacho](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@gazpacho](https://boards.straightdope.com/u/gazpacho)\ **Post date:** [September 20, 2006, 6:44pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/12 "2006-09-20T18:44:03Z")
In order to ping something the IP address needs to be known. The fact that we have a convenient architecture for quickly and easily looking this up does not change the fact that the IP address needs to be known by the pining computer. ---
**Author:** ![MrSquishy](https://avatars.discourse-cdn.com/v4/letter/m/b9e5f3/32.png) [@MrSquishy](https://boards.straightdope.com/u/MrSquishy)\ **Post date:** [September 20, 2006, 6:45pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/13 "2006-09-20T18:45:23Z")
[QUOTE=What Exit?] You are splitting hairs I think. You said “You need to know the IP address to ping it.” I was simply correcting you. I do not need to know the IP address of the Yankees, I simply ping [www.yankees.com](http://www.yankees.com) and I learn their IP address. Your statement was not correct and I was letting you know it was. I use this quite often in the office as I am more likely to know a Computer’s name then address. Jim [/QUOTE] Can’t we assume our hero is doing his hacking from a machine that wouldn’t have a reverse DNS lookup? Then you’d need to know the IP address. Right? ---
**Author:** ![Nanoda](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Nanoda](https://boards.straightdope.com/u/Nanoda)\ **Post date:** [September 20, 2006, 6:49pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/14 "2006-09-20T18:49:26Z")
I’m with **gazpacho** - internet traffic is addressed by IP, not DNS (or any other) name. If you ping [www.yankees.com](http://www.yankees.com), you are actually performing a DNS lookup on that name, followed by sending ping packets to the resulting IP address. If your selected DNS server doesn’t, for whatever reason, recognize a name, you can’t ‘ping’ it, regardless of whether the computer other exists or not. ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [September 20, 2006, 6:51pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/15 "2006-09-20T18:51:11Z")
[QUOTE=gazpacho] In order to ping something the IP address needs to be known. The fact that we have a convenient architecture for quickly and easily looking this up does not change the fact that the IP address needs to be known by the pining computer. [/QUOTE] First off, is the Computer Pining for the Fjords? 😉 I do not the IP address of most computers, I ping the computers by name and get results. To me this answers the Op as “No, I do not need to know the IP to be able to ping it”. Jim ---
**Author:** ![MrSquishy](https://avatars.discourse-cdn.com/v4/letter/m/b9e5f3/32.png) [@MrSquishy](https://boards.straightdope.com/u/MrSquishy)\ **Post date:** [September 20, 2006, 6:52pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/16 "2006-09-20T18:52:03Z")
I also meant to say that, while no guru, I know a fair bit about this stuff and the OP sounded pretty reasonable to me. The only thing I thought sounded a little low-tech to be coming out of a geek’s mouth is “security programs”. You could say something like “IDS” or “NIDS” (Intrusion Detection System/Network Intrusion Detection System) or maybe technically less correct but more accessible would just be “firewall”. ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [September 20, 2006, 6:53pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/17 "2006-09-20T18:53:05Z")
[QUOTE=MrSquishy] Can’t we assume our hero is doing his hacking from a machine that wouldn’t have a reverse DNS lookup? Then you’d need to know the IP address. Right? [/QUOTE] A new question, I would assume our hero is doing his hacking from behind a good firewall where you could not ping him even with his IP address. ---
**Author:** ![MannyL](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@MannyL](https://boards.straightdope.com/u/MannyL)\ **Post date:** [September 20, 2006, 6:54pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/18 "2006-09-20T18:54:12Z")
Regardless to ping something you either type ping \ or ping \ if you do ping \ the system has to resolve the name to a number via DNS then the ping goes to the number so at that point you do know the IP address yo uwant to ping. I know I just split hairs ---
**Author:** ![DeadlyAccurate](https://avatars.discourse-cdn.com/v4/letter/d/ac91a4/32.png) [@DeadlyAccurate](https://boards.straightdope.com/u/DeadlyAccurate)\ **Post date:** [September 20, 2006, 6:56pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/19 "2006-09-20T18:56:33Z")
[QUOTE=What Exit?] Additionally many firewalls detect, determine all probes against them with I believe a trace routine. Early on before home firewalls were common I had an PC that I used to share internet and run BLACKICE. BlackIce would report all the probes against my systems. A good hacker would not probe someones dataline without some intermediaries to prevent proper tracing. I guess I am saying your quoted exchange does not make much sense to me. [/QUOTE] I’ve pinged IPs and DNS names myself; I know a little bit about networking. But I’ve always pinged something I already knew (like Google), and I know nothing about actually trying to break into something illegally. I considered trying to contact Cult of the Dead Cow for info, but their website doesn’t really inspire much confidence (imagine that). So what would be a reasonable way for him to get caught, assuming he is a really good hacker? I do intend to leave it as simple and vague as I have it in that example; no one wants to read a how-to manual on hacking in a thriller, but I _hate_ when I see something that’s just plain wrong in books I read. ---
**Author:** ![AHunter3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ahunter3/32/368_2.png) [@AHunter3](https://boards.straightdope.com/u/AHunter3)\ **Post date:** [September 20, 2006, 7:16pm UTC](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446/20 "2006-09-20T19:16:39Z")
**MrSquishy** gets it in one. Those of you who bring up things like pinging [google.com](http://google.com) are technically right but contextually wrong. The person in the situation described by by the fictional excerpt in the OP isn’t going to have bought up a domain name and associated it with their IP address for the duration of their sneaky-footed hacking expedition. Most likely not a static IP at all. They might conceivably be pingable at something like **[pool-68-236-23-29.phil.east.verizon.net](http://pool-68-236-23-29.phil.east.verizon.net)** but you’d be even less likely to come up with that randomly assigned bunch of garbage than to just guess the IP address itself. [Next page](https://boards.straightdope.com/t/do-you-have-to-know-an-ip-to-be-able-to-ping-it/373446.md?page=2)