System-Wide Transparent FTP Tunneling with Fallback
In this example transparent FTP tunneling is configured to secure file
transfers to three different subnets (10.70.20.0/24
,
172.16.8.0/21
, and 192.168.93.0/25
). Configuration is done
system-wide affecting all FTP batch jobs and interactive sessions to those
three subnets. FTP connections to other addresses are not affected.
In this example SSH Tectia SOCKS Proxy is configured to fall back to plain FTP if
securing the connection fails. Fallback is a usable feature during the
migration phase but must be turned off once all connections are working
correctly.
Do the following steps:
- Copy the
/etc/ssh2/ssh-socks-proxy-config-example.xml
configuration file to /etc/ssh2/ssh-socks-proxy-config.xml
(if it
does not exist yet), and edit the file to enable fallback to plaintext FTP:
<filter-engine>
<dns id="id1_dns"
ip-address=".*"
pseudo-ip="NO" />
<filter dns-id="id1_dns"
ports="21"
action="ftp-tunnel"
profile-id="id1"
fallback-to-plain="YES" />
</filter-engine>
|
- Start the SOCKS Proxy if it is not already running.
If the SOCKS Proxy is already running, take the updated configuration in use as
instructed in Section Reconfiguring ssh-socks-proxy.
- Edit the system-wide FTP configuration file
SYS1.TCPPARMS(FTPDATA)
to include the following lines:
SOCKSCONFIGFILE EXAMPLE.SYSTEM.SOCKS.CONF
FWFRIENDLY TRUE
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- Create a new SOCKS configuration dataset
EXAMPLE.SYSTEM.SOCKS.CONF
with the following contents:
sockd @=127.0.0.1 10.70.20.0 255.255.255.0
sockd @=127.0.0.1 172.16.8.0 255.255.248.0
sockd @=127.0.0.1 192.168.93.0 255.255.255.128
direct 0.0.0.0 0.0.0.0
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