IPSec Tunnel Down if Adding Another Network Segment

[mhrth]

Hi, 

I am in the middle of configuring IPSec Tunnel from my FortiGate firewall to Sophos firewall. There is no issue when I add one VLAN as both Phase 1 and 2 are up. However, Phase 2 is down when I add another 2 VLANs. The settings in both firewall are similar as we refer to this documentation: https://www.sophos.com/ja-jp/medialibrary/PDFs/documentation/SophosFirewall/Pocket-Guides/Establish-...

Thank you in advance :)

[akristof]

Hello,

You mean when you are adding another Vlan subnet as a separate phase2, all phase2s are down and not negotiating?

[mhrth]

Hello,

Correct. When adding another VLAN subnet as separate phase2, all phase 2 down.

Matin

[akristof]

Hello,

In that case, run ike debug:

https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-IPSEC-Tunnel-debugging-IKE/ta-p/1900...

When it will be running, via GUI make all phase2s up and see what is the problem. You can put the result into file and attach it. Just tell me which tunnel are we talking about if the output will have more of them.