pings & firewalls

Im sure everyone who has pinged someone will quite often not get an answer. I then learned that firewalls tend to block ICMPs. Does this automatically mean that when I ping a host, and I get no response, that the host has a firewall installed?(or a has a router perhaps) Furthermore, if both of these options are candidates... how do I find out if it is a firewall or a router blocking my pings? :confused:

Hello,

While I'm not sure on how to tell 'what type' of firewall is blocking you;
You are correct that it can be either a hardware firewall (router) or software firewall.

Its very common for many people and most companies to use routers with hardware firewalls that prevent any ICMP traffic as to eliminate the threat of a network being ping flooded... (Also just to remain that much more 'private')

RRP

i think you answered your own question, if your pings are being blocked, then either the IP you are trying to ping isnt active, or it has a firewall installed that is blocking all of your incoming pings. Most large sites (such as antionline.com) refuse pings.

Since there is no traffic being returned its nearly impossible to tell if it is a router or a firewall.

NMAP can tell you whether the host is firewalled or is actually down. It can perform other tasks as well, such as OS fingerprinting(if that is something that would be interesting for you to know about the host.)
-NeuTron

Thanks for clearing this up... its been confusing me for a while...not anymore, ty.

Well, if a ping doesn't get through to your target machine, while, yeah, it could be that it's firewalled, it could also simply mean that the target machine is down. To see if it's firewalled, you could try running a trace route to the target machine. If the trace route get through to the target machine and you see stars (*****) as a hop, that particualar hop is a firewall. Granted, the firewall could be declining trace routes as well, but it's worth a shot and just as easy to run as a ping.

alpha

[gloworange]When,How,and What is ping for? sorry i'm just a newbie just curious..is it neccesarry to ping?[/gloworange]

Quote:

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...and you see stars (*****) as a hop, that particualar hop is a firewall...

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Actually, the ip just before the ***** is usually the firewall. :)

pixelrockchick, Oh man... wait til im either not so tired or I grab my sexy matrix styled sunglasses then put them on. Your sig annoys me and so does the yellow text that also hurts my eye-balls aswell.

Ok ping...
Go to DOS AKA "command promt"
ping 127.0.0.1 -w 3000
ping is the ping command, 127.0.0.1 is a example IP address, -w 3000 is a wait of 3000 milliseconds or also known as 3 seconds.

|The|Specialist sarcasticly says: Oh gezz... that as about 100 times easier than a game of pong, & once you've both pinged and played the game pong wouldn't you agree? :o You can mainly use ping to see if a box is online and stuff like that.