ftp problem

To: lvs-users@xxxxxxxxxxxxxxxxxxxxxx
Subject: ftp problem
From: Stefan Peter <stefan@xxxxxxxxxxxxxx>
Date: Thu, 25 Jul 2002 08:28:11 +0200 (CEST)
Hi All,

I'm new in LVS, and I have built up an LVS cluster including 4 RSs and 2
distributors. Keepalive failover works suprisingly well, and the whole
cluster serves DNS, HTTP, HTTPS, telnet, mail, POP3, IMAP and FTP.
Every service works well except active FTP. I have read trough howtos and
mailing lists but I have found no help to my problem. (Maybe I was too

FTP service is set to be persistent at 720 for both TCP ports 20 and 21.
Suppose connect the cluster using a command-line FTP client: connection is
established on port 21 to RS1. Then I issue an ls command, and another
connection is built on port 20 to the same RS. Then I wait for FTP
timeout, and I issue ls command again:

ftp> ls
421 No Transfer Timeout (300 seconds): closing control connection.
ftp> ls
Not connected.

Then I try to reconnect and when I issue ls, there is no prompt response,

ftp> ls
200 PORT command successful.
425 Can't build data connection: Connection timed out

On the distributor it can be seen that connections point to different RSs
for ports 20 and 21.

[root]# ipvsadm -Lc
IPVS connection entries
pro expire   state       source            virtual           destination
TCP 14:55.19 ESTABLISHED client:4407       vs:ftp            rs1:ftp
TCP 01:42.27 FIN_WAIT    client:4376       vs:ftp            rs1:ftp
TCP 11:55.19 NONE        client:0          vs:ftp-data       rs2:ftp-data
TCP 01:51.27 NONE        client:0          vs:0              rs1:0
TCP 00:58.18 SYN_RECV    client:49290      vs:ftp-data       rs2:ftp-data

What's wrong?

Best Regards,
Peter Stefan

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