On Tue, Oct 28, 2003 at 09:14:43AM -0500, Steve Bellovin wrote:
> I'm having trouble logging in to ftp.netbsd.org by v6.  There is 
> connectivity, and v4 works, but with v6, ftpd seems to hang after 
> receiving the PASS command.
> 
> # ftp -d -6 -a ftp.netbsd.org
> Connected to ftp.netbsd.org.
> 220 ftp.NetBSD.org FTP server (NetBSD-ftpd 20020615) ready.
> ftp_login: user `<null>' pass `<null>' host `ftp.netbsd.org'
> ---> USER anonymous
> 331 Guest login ok, type your name as password.
> ---> PASS XXXX
> 230-
>        <***************************** LONG PAUSE HERE

At that point, ftp.netbsd.org usually replies with a 1500-byte long
packet. Make sure you negociate a correct MSS in case you have a
MTU black hole, like in a lot of PPPoE setups.

Quentin Garnier.