Lost Https Access

[MohammedAlrawi]

Hi 

Am facing a strange issue where when I uploaded the backupconfig of the firewall we lost https or http access to the firewall I will explain everything below (I did a session with forti support but the result was you shouldn't take back up config from 7.6.0 version to 7.2.10 version tbh I wouldn't say this is true at some point but I will try my lost hope here)

So we have a fortigate firewall that is on 7.6.0 we wanna role back because this version is seriously bad I toke the passive firewall factory reset it also rolled back to 7.2.10 then toke the back up config from 7.6.0 and uploaded it in the 7.2.10 suddenly no https \ http access I will write everything down that I tried : 
1-interface up allow access ping https http ssh(i can ssh into the firewall)

2-change the https port to default 

3-no local in policy is configured

4-trust host is configured I added the whole subnet of my vlan (me and the firewall are on the same vlan)

5-diagnose sniffer to see what is being blocked when i try https there something wrong with the tcp connection I will list below the log

1.873909 172.20.0.31.59812 -> 172.20.0.56.443: syn 3386744634
1.874091 172.20.0.56.443 -> 172.20.0.31.59812: rst 0 ack 3386744635

after many search it turns out there is issue with the tcp connection but I still couldn't understand why am not getting https access could anyone help me here? 


many thanks in advance.

[abarushka · Accepted solution]

Hello,

FortiOS 7.6.0 doesn't support downgrade:

"Downgrading to previous firmware versions results in configuration loss on all models."

https://docs.fortinet.com/document/fortigate/7.6.0/fortios-release-notes/687629/downgrading-to-previ...

[dingjerry_FTNT]

Hi @MohammedAlrawi ,

We never know what will happen if you load an incompatible version of the config to the FortiGate. 

In your case, your backup config is 7.6.0 based and your FGT is 7.2.10.   The versions are not matching so we can't guarantee anything about it.

You have to convert the 7.6.0 config to 7.2.10 config, then reload it to the FGT.

You can convert it manually, or using FortiConverter if you have one.