Re: [ftpext] FTP64 LANGuage [was RE: [BEHAVE] one week WGLC, draft-ietf-behave-ftp64-05]

Iljitsch van Beijnum <> Wed, 05 January 2011 14:17 UTC

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From: Iljitsch van Beijnum <>
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Date: Wed, 5 Jan 2011 15:19:29 +0100
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To: Dan Wing <>
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Subject: Re: [ftpext] FTP64 LANGuage [was RE: [BEHAVE] one week WGLC, draft-ietf-behave-ftp64-05]
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On 3 jan 2011, at 21:38, Dan Wing wrote:

> For whatever it's worth, I checked the FTP ALG for NAT44 in Cisco's
> IOS, and it does nothing special with LANG (it doesn't block the
> command nor parse the FEAT response).  We have other ALGs in other
> products (e.g., Linksys, ASA), but I did not check those.  Our bug 
> database (which spans all Cisco-branded products) has no customer 
> complaints about FTP's LANG support.

Apparently nobody else can muster up the energy to care about this.

I'm ok with adding a SHOULD for supporting LANG in the ALG so that if a server and client negotiate a non-default language the ALG also participates. This assumes the ALG supports the negotiated language, but I'm thinking that if the server and client support a non-default language, there's a good chance that the ALG vendor either added this language too, or allowed sufficient customization for the user to do this. The ALG only has 10 or so responses that it can generate, after all.

But for the reasons I outlined earlier, I'm still very reluctant to make this a MUST. Seeing as the FTP44 ALG people apparently managed to do without this, such a requirement runs a big risk of becoming a dead letter, anyway. There's enough of that when it comes to FTP specifications...