Connecting iscsi from an external network, are there any restrictions?

Question

ubuntu

Good afternoon.
Created target on ubuntu 20.04.
Network: static ip --> router --> Windows PC ip 192.168.0.103
--> raspberry ubuntu server 192.168.0.104

Port forwarding is done on the router 3260 to 3260 192.168.0.104
When initializing from home PC (specifying external ip) everything is OK , there is a connection, the disk is detected ready for use.
When initialized from an external network (different city) --> discovery occurs, but when connected to the target object - an error.

if you do the same on linux (from an external network), there is also an error:
``` sudo iscsiadm -m node --targetname "iqn.2003-01.org.liaux-is csi.ubuntu.zzzz:sn.6a3zzzzz06" --portal "192.168.0.104:3260" --login
Logging in to [ iface: default, target: iqn.2003-01.org.linux-iscsi.ubuntu.armv7l :sn.6a35d032fc06, portal: 192.168.0.104,3260] (multiple)
iscsiadm: Could not login to [iface: default, target: iqn.2003-01.org.linux-iscsi.ubuntu.armv7l:sn.6a35d032fc06, portal: 192.168.0.104,3260].
iscsiadm: initiator reported error (8 - connection timed out)
iscsiadm: Could not log into all portals
```

Answer 1

Forwarding an iscsi target through external channels is a bad idea - the disk will constantly fall off by timeout at the slightest delay on the channel. Your problem, most likely, is that you have the same subnet at different sites. The connection does not go to the router, since the destination address is from the local subnet.