[Nottingham] How to enable echo (for ping)

Martin nottingham at mailman.lug.org.uk
Wed Jul 30 18:48:01 2003

James Beckett wrote:
> Martin wrote:
>> ping works fine out to my ISP, but 'ping localhost' has 100% packet 
>> loss. localhost resolves to ok, and iptables count the 
>> packets on the ACCEPT rules ok.
>> So far I've tried:
>> chkconfig echo on
>> /etc/init.d/xinetd reload
> The echo service in x?inetd is entirely unrelated to the ping (ICMP)
> echos you're looking for.


> The echo service will echo back a TCP stream
> you send to it, eg with
>     telnet localhost echo
> More than likely, you don't need it enabled.

Beautifully obscure! I'll have a brief play before disabling it...

> Can you ping your box from another?

No. (Or rather, there's no response.)

> Can you telnet localhost?
>         telnet localhost 80? etc

No... Not got telnet installed!
I can access localhost services though. For example, I have SetiQueue 
running under Wine for the Seti@home project. I can access the SetiQueue 
  served web pages fine (http://localhost:5517).

> In /etc/sysctl.conf do you have a line like
>     net.ipv4.icmp_echo_ignore=1 ?

Got one better than that!

How about:


Now for a few more tweaks, including

Many thanks!

(And where in manuals is there a pointer to that!)

Martin Lomas