Cannot download some files from a given server

Question

I'm working on a Fedora Core release 6, and whenever I want to download a given file from a FTP site, the connection is refused:

  $ curl --ftp-pasv  "ftp://ftp.ensembl.org/pub/current_mysql/vega_mart_56/CHECKSUMS.gz" 
  curl: (7) couldn't connect to host
  $ wget "ftp://ftp.ensembl.org/pub/current_mysql/vega_mart_56/CHECKSUMS.gz"
  --14:25:46--  ftp://ftp.ensembl.org/pub/current_mysql/vega_mart_56/CHECKSUMS.gz
             => `CHECKSUMS.gz'
  Resolving ftp.ensembl.org... 193.62.203.113
  Connecting to ftp.ensembl.org|193.62.203.113|:21... failed: Connection refused.

Downloading from a HTTP server is OK.

is it a firewall problem ? How can I fix this ? (The sysadmin is in holidays... :-) )

Thanks

Answer 1

Works on my machine. If anything, I'd say it's firewall-related.

Answer 2

Chances are it's not a software firewall on the system, that'd be wacky. But you can check by doing (as root):

iptables -L OUTPUT

I suspect you'll see something like:

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination   

Which means nothing on the system is blocking that connection. It is possible it's a firewall within your infrastructure, but you haven't told us if you have a firewall, what kind it is, if you have access, etc. All I can tell you is I am able to download that file via FTP from where I am. :)

Answer 3

Either that remote host is refusing your connection or, more likely, you've got firewall rules somewhere preventing connections to Internet hosts, TCP port 21, from your source host.

We'd need a lot more information to tell you where to start looking. There could be iptables rules on the host where you're sourcing that connection. There could be rules in a firewall elsewhere on your network.