Subject: login problems from certain hosts

From: "Steve Newell" <[email-masked]>
Date: Wed, 17 Jul 1996 17:41:01 +0000

I have installed wu-ftpd 2.4.2.beta on a linux box.  It seems to be running quite 
well for the majority of users that try to access my site.

I am, however, having problems with a small subset of users.  For 
example, when one user tries to login, the server immediately kicks 
him off.

Looking in my /var/adm/syslog, I see the following:

Jul 17 16:04:10 linux wu.ftpd[844]: warning: can't verify hostname:gethostbyname(oneseventeen246.metawire.com) failed 
Jul 17 16:04:10 linux wu.ftpd[844]: refused connect from 204.80.117.246

I have no ftphosts file, nor can I find anything obviously wrong with 
my ftpaccess file.

Anyone have any ideas?

Thanks,

Steve
/*************************************************/
/*                  Steve Newell                 */
/*                [email-masked]             */
/*                Roberts-Slade, Inc.            */
/*************************************************/

---

From: Michael Brennen <[email-masked]>
Date: Wed, 17 Jul 1996 23:54:39 -0500 (CDT)

On Wed, 17 Jul 1996, Steve Newell wrote:

> Jul 17 16:04:10 linux wu.ftpd[844]:
  warning: can't verify hostname:gethostbyname(oneseventeen246.metawire.com) failed 
> Jul 17 16:04:10 linux wu.ftpd[844]:
  refused connect from 204.80.117.246

This is a DNS mismatch for the site that failed.  Looks like you're
running ftpd from behind tcp wrappers and wrappers is configured or
compiled with PARANOID. 

Two nslookups are below.  The first does the reverse lookup on the IP
address, then tries to verify that name with a forward lookup.  Oops --
didn't match.  PARANOID will refuse a connect from such a site.

The answer is to fix the DNS, not remove PARANOID.

/etc# nslookup 204.80.117.246
Server:  ns1.fni.com
Address:  204.181.104.1

Name:    oneseventeen246.metawire.com
Address:  204.80.117.246

/etc# nslookup oneseventeen246.metawire.com
Server:  ns1.fni.com
Address:  204.181.104.1

*** ns1.fni.com can't find oneseventeen246..metawire.com: Non-existent 
host/domain

   -- Michael