newbie: rh6.2 telnet performance...

[Peter Barker]

On Mon, 20 Aug 2001, Jerry Cashman wrote:

> I'm very new to this linux thing, and am trying to learn meself some RedHat.
> (yee haaa)

Ride awn...

> The network is pretty damn simple... a straight (twisted) cable connects the
> linux box and laptop! No hubs, routers, etc etc etc...

I assume you're talking about a "crossover" cable here - or one of your
machine auto-detects a null-link.

> inetd is running as is telnetd and ifconfig tells me that eth0 is UP and
> running...

Ob. security. Make sure your telnetd is either up-to-date or disabled on
any external interface. I have a suspicion there may be a serious problem
with the current telnetd bug at some stage.

> Here's the problem... when I try to telnet to the linux box from my laptop,
> I get a very extended (like, several minutes) delay before it replies with a
> login prompt!
> 
> When I start my telnet client is connects straight away, I'm pretty sure the
> linux box knows that there is someone at the door, 'cause it's ancient old
> hard-disk rattles nicely for a second or two as soon as I try to connect...

This smells like a DNS issue. When trying to log the connection from the
"other box", telnetd is blocking waiting for a response to a name-server
query.

To verify this, you could try using strace.

If this is the problem, dropping an entry in /etc/hosts should fix it.

> Jerry Cashman

Yours,
-- 
Peter Barker                          |   N    _--_|\ /---- Barham, Vic 
Programmer,Sysadmin,Geek              | W + E /     /\                
pbarker at barker.dropbear.id.au         |   S   \_,--?_*<-- Canberra      
You need a bigger hammer.             |             v    [35S, 149E]   
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