[hobbit] Dumb hobbit network test question

Kauffman, Tom KauffmanT at nibco.com
Wed Nov 30 23:51:57 CET 2005


Oh, how it helps to have additional minds on these things.

Reverse lookup looks to be the culprit. I cloned all these systems in a
bit of a hurry -- and the cloning changed the dns resolution config to
point at (in order) my D/R hotsite Win2003 domain controller (active),
my D/R hotsite D/R test domain controller (non-existent), my D/R hotsite
hobbit system (also not there), and THEN my local DNS server -- so if
the D/R DC didn't answer (wonder why IT goes away every two hours?) I
would go through multiple retries to non-existent systems.

One more item added to the system clone checklist.

Thanks!

Tom

-----Original Message-----
From: Henrik Stoerner [mailto:henrik at hswn.dk] 
Sent: Wednesday, November 30, 2005 4:59 PM
To: hobbit at hswn.dk
Subject: Re: [hobbit] Dumb hobbit network test question

On Wed, Nov 30, 2005 at 03:38:56PM -0500, Kauffman, Tom wrote:
> Henrik, can you clarify what this really means?
> 
> Address=10.8.224.9:21, open=1, res=0, err=1, connecttime=0.003110,
totaltime=10.063026,

"open=1" means that the connection to the server succeeded. The
interesting thing here is that it took only 0.003 seconds to get a
connection, but then Hobbit spent more than 10 seconds waiting for a
banner to appear. It never did - at least not within those 10 secs;
the "err=1" means it gave up waiting for the data and signals a timeout.

> Address=10.8.224.38:21, open=1, res=0, err=0, connecttime=0.003060,
totaltime=0.028471, 
>   banner='220 wabash FTP server (Version 4.2 Sat Feb 5 10:12:55 CST
2005) ready. 221 Goodbye.' (86 bytes)

This is a different server. Again, connecting takes about 0.003 secs,
but the banner appears almost immediately - the entire exchange happens
in 28 milliseconds.


It might be that the FTP server performs a reverse DNS lookup of the
Hobbit servers' IP address when Hobbit connects to check the FTP
service. Sometimes DNS lookups take a while - maybe long enough for
Hobbit to reach the 10 seconds timeout. Maybe your ftp server has 
a local DNS cache, and the timeout only happens when the cached DNS
entry expires and has to be refreshed.

One thing you can try is to add a "--timeout=30" option to the
bbtest-net command in hobbitlaunch.cfg; that makes it wait up to 30
seconds before flagging a timeout.


Regards,
Henrik


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