[Nottingham] How to enable echo (for ping)

[Martin]

James Beckett wrote:
> Martin wrote:
> 
>> ping works fine out to my ISP, but 'ping localhost' has 100% packet 
>> loss. localhost resolves to 127.0.0.1 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:
net.ipv4.icmp_echo_ignore_all=1

(:-))

Now for a few more tweaks, including
net.ipv4.icmp_echo_ignore_all=0



Many thanks!

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



-- 
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Martin Lomas
martin@ml1.co.uk
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