FW: ECHO Protocol

[Hurst, Dave]

The "echo" service referred to in the local services file is an old Unix service typically implemented directly in inetd.  It listens on port 7 and echos back any data sent to it.  Typically, the echo service should be turned off because it performs no useful service and is a potential vulnerability. 

 

This is completely different from the ICMP echo-request/echo-reply codes used to implement ping. 

 

--DaveH         "Be Excellent to each other!"

-----Original Message-----
From: firewall-wizards-bounces@... [mailto:firewall-wizards-bounces@...]On Behalf Of peng liu
Sent: Monday, June 30, 2008 10:12 PM
To: Keith A. Glass; firewall-wizards@...
Subject: Re: [fw-wiz] ECHO Protocol

OK. This is the tricky part since ICMP is built basd on IP protocol and it works on thesame layer as TCP/UDP. Then why my local services file contains:

 

echo                7/tcp
echo                7/udp

 

So the echo here is different than the Echo, Echo-reply protocol we are talking here?

 

Regard,

Pengy

 

On 6/30/08, Keith A. Glass <salgak@...> wrote:

Echo is a specific member of the ICMP family of protocols.  But not the ONLY member. . .

Ping is typically Echo and Echo-reply.

Hope that clears it up


Keith

Security Geek  * Curmudgeon at Large *  Short on Sleep

On Thu Jun 26  6:00 , "peng liu"  sent:

>All,
>
>I am checking the ICMP protocol these days and some documents say that Ping command in Windows uses ICMP protocol, while others say that Ping uses ECHO protocol, which is through TCP port 7.
>
>So my question is which protocol is actually used by PING command in Windows?
>
>Pengy

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