FTP Issue for Inbound connections

[jasonw]

Not sure what is wrong but something has broken lately with inbound FTP connections. we update to 9.1(6) and sense then Active FTP connections just don't work correctly. Can some one help?

[joseoroz]

Hello Jason,

If the clients are behind the firewall and active FTP is being used it will require to have the FTP inspection enabled.

You can confirm if this is enabled with the command show run policy-map.

Can you provide the output from the command show service-policy if you have the inspection enabled.

http://www.cisco.com/c/en/us/support/docs/security/asa-5500-x-series-next-generation-firewalls/113110-asa-enable-ftp-00.html

If the connections are being established you can setup a capture with a circular buffer and confirm what happens at the end of the communication and analyse it with a packet sniffer.

http://www.cisco.com/c/en/us/support/docs/security/asa-5500-x-series-next-generation-firewalls/110117-asa-capture-asdm-config.html

[jasonw]

here is the show run-policy

-------------

Policy-map type inspect dns preset_dns_map
 parameters
  message-length maximum client auto
  message-length maximum 512
policy-map global_policy
 class inspection_default
  inspect dns preset_dns_map
  inspect ftp
  inspect h323 h225
  inspect h323 ras
  inspect ip-options
  inspect netbios
  inspect rsh
  inspect rtsp
  inspect skinny
  inspect esmtp
  inspect sqlnet
  inspect sunrpc
  inspect sip
  inspect xdmcp
 class class-default
  user-statistics accounting

-----------

[joseoroz]

The inspection is enabled. Now as I recommended before you may setup captures on the firewall to analyze the traffic and be able to determine the reason for the failure.

Can you confirm what is the problem. Are the connections failing to be established ? Are the connections dropping after a while?

You can run your test and gather the show service policy prior and after and confirm if there are drops related to the FTP inspection and if the counter increases.