Forum Discussion

LeanderV_365921's avatar
LeanderV_365921
Feb 07, 2019

FTP Proxy , user based forwarding with iRule

Im looking into using a VS as an FTP Proxy towards my backend webserver. Currently i already works for one webserver behind the VS. Im now trying to write an iRule to forward traffic to the right s...
application delivery
devops
ftp
irule
iRules
LTM
payload
tcp
Andy_McGrath's avatar
Andy_McGrath
Icon for Cumulonimbus rankCumulonimbus
Feb 19, 2019

From what I have seen FTP 

PASS
command is sent separately following a 
331
request from the FTP server.

This is from an example PCAP file I found online:

< 220-
< 220 6bone.informatik.uni-leipzig.de FTP server (NetBSD-ftpd 20041119) ready.
> USER anonymous
< 331 Guest login ok, type your name as password.
> PASS IEUser@
< 230 Guest login ok, access restrictions apply.
> opts utf8 on
< 502 Unknown command 'utf8'.
> syst
< 215 UNIX Type: L8 Version: NetBSD-ftpd 20041119
> site help
< 214-

If this is the case for your client and server I would expect the F5 can simply pass through the password in the next payload.

It is possible that different authentication methods are available (Hit this issue when writing extract iRule for SMTP authentication) so you would need to check as I do not know FTP in that much detail.