topic Re: FTP from Firewall to device in encryption domain in Network Security

FTP from Firewall to device in encryption domain

Brad_Shawh — Thu, 23 Apr 2020 06:31:42 GMT

I have a site to site VPN from Site A to Site B.

Site A : 10.110.11.0/24

Site B : 10.0.0.0/8 Network

Behind Site B's firewall, we have an FTP server (10.x.x.x)

There is a default route on Site A that points to Gateway (ISP's IP address).

I am trying to take backup of the firewall using the following command

backup /noconfirm location ftp://username:password@10.x.x.x/backups/"

On the monitoring, I get the following logs

Apr 23 2020

06:14:50

302013

x.x.x.x (gateway IP)

22632

10.x.x.x

Built outbound TCP connection 5098542 for outside:10.x.x.x/21 (10.x.x.x/21) to identity:x.x.x.x/22632 (x.x.x.x/22632)

Apr 23 2020

06:15:00

302014

10.x.x.x

x.x.x.x

22632

Teardown TCP connection 5098542 for outside:10.x.x.x/21 to identity:x.x.x.x/22632 duration 0:00:10 bytes 0 SYN Timeout

x.x.x.x = Gateway IP Site A's firewall.

I believe traffic can't be initiated from the Firewall to encryption domain, is there a way to take backup here?

Re: FTP from Firewall to device in encryption domain

Rob Ingram — Thu, 23 Apr 2020 08:59:09 GMT

Hi,
Include the outside IP address of Site A firewall in the ACL defining the interesting traffic (encryption domain). Obviously mirror this on Site B firewall aswell.

HTH

Re: FTP from Firewall to device in encryption domain

Brad_Shawh — Thu, 23 Apr 2020 19:30:40 GMT

Thank you.

That did not help.

The connection from Firewall to FTP server goes fine, then next log entry is syn timeout.

Apr 23 2020

19:27:22

302014

10.x.x.x

x.x.x.x

3195

Teardown TCP connection 5124890 for outside:10.x.x.x/21 to identity:x.x.x.x/3195 duration 0:00:10 bytes 0 SYN Timeout

Re: FTP from Firewall to device in encryption domain

Rob Ingram — Thu, 23 Apr 2020 19:39:57 GMT

Does it establish an IPSec SA for that communication?
Have you defined a rule in the ACL permitting this communication?

Your return traffic from the FTP server 10.x.x.x could be unintentially natted, ensure you have a NAT exemption rule in place.

Run packet-tracer to test the communication and provide the output
Run a packet capture on the firewall and provide the output.

Re: FTP from Firewall to device in encryption domain

Brad_Shawh — Thu, 23 Apr 2020 21:48:00 GMT

Does it establish an IPSec SA for that communication? : Yes

Have you defined a rule in the ACL permitting this communication? : Yes

Your return traffic from the FTP server 10.x.x.x could be unintentially natted, ensure you have a NAT exemption rule in place.

I added the public IP to NAT exemption.

Packet tracker : Please let me know the parameters for packet tracer.

Run a packet capture on the firewall and provide the output : What parameters please?

Re: FTP from Firewall to device in encryption domain

Brad_Shawh — Mon, 27 Apr 2020 12:04:04 GMT

Bump!

Any hint please?