New IP segement cannot establish FTP session

[Migzy]

Hi,
We recently have a new IP segment in our network and assgined this IP to one of our Windows server(172.22.4.xxx). Whenever the window server tries to connect to the HP uX server FTP. It cannot established a session. Ping and telnet to port 21 is successful from WIn server to the HP UX. But will only prompt Connected to 172.22.38.xx ( HP UX server), then it pormpts connection lost
Cheked the HP UX log and found the ff:

an 11 16:06:38 PNBFAMD1 inetd[17023]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:06:38 2010
Jan 11 16:11:36 PNBFAMD1 inetd[17266]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:11:36 2010
Jan 11 16:16:37 PNBFAMD1 inetd[17516]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:16:37 2010
Jan 11 16:21:37 PNBFAMD1 inetd[17761]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:21:37 2010
Jan 11 16:26:41 PNBFAMD1 inetd[18003]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:26:41 2010
Jan 11 16:31:36 PNBFAMD1 inetd[18246]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:31:36 2010
Jan 11 16:36:38 PNBFAMD1 inetd[18506]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:36:38 2010
Jan 11 16:40:20 PNBFAMD1 inetd[18675]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:40:20 2010
Jan 11 16:46:36 PNBFAMD1 inetd[18981]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:46:36 2010
Jan 11 16:50:50 PNBFAMD1 ftpd[18506]: lost connection to 172.22.4.7 [172.22.4.7]
Jan 11 16:51:38 PNBFAMD1 inetd[19243]: ftp/tcp: Connection from unknown (172.22.4.7) at Mon Jan 11 16:51:38 2010



BTW the WIn server is hosted on a HP Blade device. BOth servers are inside a PIX Firewall. Policy has been set to allow anything from both segment. Other IP segment with the same setup 172.22.3.xxx can connect successfully. CAn you help us determine why the connection fails. Thanks.

[Ivan Krastev]

Check /var/adm/inetd.sec for ftp restrictions.

[Migzy]

Hi Ivan,

Thanks for the reply, unfotunately we did not configure the /var/adm/inted.sec and only let the FW do the security. On the FW side, static config is setup such the win server ( inside) is recognized on the HPUX segment same with the 172.22.3.xxx (inside) that can sucessfully do ftp. no access list provided since it is in the same fW but in a different DMZ. What could be wrong in our setup?

[rick jones]

I believe those entries simply mean that inetd attempted to map the IP address back to a hostname and was unsuccessful.

FWIW, it is considered a best practice to have "PTR" records in the DNS mapping IP addresses back to hostnames.

I do not know if ftpaccess(4) has a setting where the ftpd will insist on a hostname but it might be worth a look. Same for inetd. As an experiment you might consider adding some name with that IP address to the /etc/hosts file (assuming your /etc/nsswitch.conf is configured to include "files" in addition to "dns" and/or any other name resolution mechanism you are using.