Does 'ftp ftp.netbsd.org' work for you if you are using IPv6
transport? I get 'Connected to ftp.netbsd.org.', but no prompt.
It works if I am using v4 transport.

spock$ traceroute6 -q 1 -l ftp.netbsd.org
traceroute6 to ftp.netbsd.org (3ffe:8050:201:1860:2a0:c9ff:feed:b7ea) from 2001:610:508:1001:260:1dff:fef6:7ff9, 30 hops max, 12 byte packets
 1  kirk (2001:610:508:1001:220:afff:fec6:4faa)  3.242 ms
 2  surrogate.ipv6.surfnet.nl (2001:610:508:1000::1)  28.773 ms
 3  surfnet-bv.Amsterdam.ipv6.surf.net (2001:610:0:2001::1)  37.053 ms
 4  PO4-0.CR2.Amsterdam1.surf.net (2001:610:16:3048::49)  23.888 ms
 5  PO0-0.BR2.Amsterdam1.surf.net (2001:610:16:6004::6)  21.25 ms
 6  ams-ix.sara.xs4all.net (2001:7f8:1::a500:3265:1)  20.824 ms
 7  *
 8  3ffe:800::fffb:0:0:5 (3ffe:800::fffb:0:0:5)  243.801 ms
 9  *
10  3ffe:8050:ffff::fffd (3ffe:8050:ffff::fffd)  659.375 ms
11  ftp6.netbsd.org (3ffe:8050:201:1860:2a0:c9ff:feed:b7ea)  403.515 ms
spock$

spock$ ftp  204.152.184.75
Connected to 204.152.184.75.
220 ftp.netbsd.org FTP server (NetBSD-ftpd 20020201) ready.
Name (204.152.184.75:rvdp): ftp
331 Guest login ok, type your name as password.
Password:
230-
                                                                            
     Welcome to FTP.NetBSD.ORG
<snip>

spock$ ftp ftp.netbsd.org
Connected to ftp.netbsd.org.
<hang>

I am not getting any packets from 3ffe:8050:201:1860:2a0:c9ff:feed:b7ea.

Can anybody check the back route from ftp.netbsd.org to 2001:610::/35?

	rvdp