hanging telnets and ftps

[Moffat]

CCVJ at lure.latrobe.edu.au writes:

>Has anyone seen this sort of behaviour before, or can any network 
>gurus point me in any directions?
 
 I have seen enough of it in the last three days to want to go to the gym to
 develop enough strength to throw our 730 out the window *B^)

>We have three RS6000s, two model 540s and one model 530, all running 
>at the same level (03.01.0001.0003).  All three are on the same 
>sub-network, have identically configured tcpip for nameserver, 
>netmasks, broadcast...etc, but one of the 540s periodically loses its 
>ability to translate names to addresses for ftp and telnet. (ping it 
>can do and "host node" returns numbers which have had to be gotten from 
>the nameserver!).

We have two 320s & a 730 with two ethernet interfaces, all at 3001, same
mask, no nameserver. I'm trying to get the 730 to act as a router to the
320s on a subnet. The 320s appear OK but the 730 keeps exhibiting these
symptoms but not always immediately - I have not yet found anything hard to
cause it.

>I have run telnet with netdata toggled, and get no output (by name -
>it works by number). I have put the names and addresses of our most 
>frequently accessed machines in /etc/hosts and the behaviour is strange.  
>With a name in /etc/hosts, ftp or telnet will work - but with a terribly 
>long delay, long enough to make most users ^C out of it.  However, using 
>the address, the response is virtually immediate.  (Is this because it 
>tries to resolve the name first?)

Using netstat -r (as smit does) to display the routing tables hangs for
about 8 minutes, whereas netstat -rn is immediate. Sometimes route -f also
hangs (I don't know for how long, I've always ^C'ed it)  Doing a rmdev -l
inet0 -d' will cure the hang (I'm not sure what it's doing, exactly, but I'm
into some desperate hacking)  All the hosts names are in /etc/hosts.
-An aside: I have noticed that using smit to add hosts on occaisions will
produce a corrupted /etc/hosts - extra or misplaced comments, from memory.
My host name is the name associated with the subnet address, not the main
net address, I was wondering about this. Also I have been adding/deleting
routes directly with route, should I perhaps be using smit totally?  (I have
not yet experimented with these, I'm taking some sanity time to read the
news) 

> I can cure the problems by flushing the routing tables and restarting
>routed

My problems occur whether routed is running or not!

A direct question: should I specify the -g (gateway) parameter when starting
routed? I have RTFM, the 'How to configure routed' man page is about as
useful as tits on a bull - its a paraphrase of the routed man page.

>Thanks,
Me too

-- 
    Graeme Moffat,                        Phone : +64 9 737 999  x8384 
    Computer Aided Design Centre,         Fax   : +64 9 366 0702
    School of Engineering,		  Mail  : Private Bag, Auckland, NZ
    University of Auckland		  Email : g.moffat at aukuni.ac.nz