RH5.2, 2.2.10, Can't Login from machine without DNS...

[Rick Coloccia <coloccia geneseo edu>]

Hi...

Normally I would browse archives, etc, before posting to a list, bit 
according to RedHat's site,

"The Red Hat mailing list archive search is currently unavailable due to 
the SEC's required "quiet period" associated with the proposed IPO of our 
stock. The search will be available again as soon as the quiet period is 
over. Thanks for your patience in the interim."

I don't know how long this will be, so here's my problem:

I have 2 dell PowerEdge 4100s (Dual Pentium Pro 200s) each with 128MB ram 
running RH5.2 w/ 2.2.10 kernel.  All RedHat rpm upgrades (as of 7/20/1999) 
have been applied.

Anyone who telnets into the machines from an IP address that DOESN'T have 
name service can not log in.  If you try, you get presented with a login 
prompt, you can feed it your password, and then you are promptly 
disconnected.  If you telnet in from a machine that does have name service, 
everything is just fine.

I have another machine, identical, on which I have RedHat 5.2 out of the 
box.  A user coming in from a machine without name service CAN log into 
this machine.

Since I need to be able to allow users coming in from machines without DNS, 
I need to know what changed in the ~25 rpms I've installed because they are 
security fixes to disable this login, so that I can "re-break" it.

Before I go and install rpms one at a time, I was hoping someone out there 
has seen this and knows what I need to do to enable machines  w/o dns to 
log in.

TIA,

-Rick Coloccia