Fortigate drop my connection

[gashjaei]

Hello Experts,

I have a one Fortigate ( 80F) with last version of firmware(FortiOS v7.0.3 build0237). 

I added some policies on it and installed it for our client.

Our client claim that he can not access to their local server which is in same IP range, I mean for example from 192.168.1.2 can not access to 192.168.1.250. He claim that when restarting the Fortigate its working fine but after for example 5 hours again Forigate  dropping all connection and as result again he can not access to their server. 

Have you ever seen this kind of issue? 

Could you please give me some advice? 

Thank you, 

Ghasem

[mariopugliese]

Hi Ghasem

Check your ARP tables when this issue occurs.

On the FGT: 

• # get system arp | grep 192.168.1.2
• # get system arp | grep 192.168.1.250

https://docs.fortinet.com/document/fortigate/7.0.1/administration-guide/473534/arp-table

Is the association between IPs and mac addresses correct from the Fortigate firewall ?

And also on the concerned servers (arp -a) ?

Do you have any Virtual IP configured on your Fortigate firewall ? (Policy and Objects => Virtual IPs) ?

It could be interesting to capture the ARP packets

# diagnose sniffer packet YOUR-LAN-INTERFACE "ether proto 0x0806"

https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-Using-the-FortiOS-built-in-packet-sn...

[gashjaei]

Hello

Thanks for your comment.

Let me check and I will back to you ( hope not :D ). For the moment there is no any issue. 

I hope FGT keep it all configuration on his memory and doesn't drop any connection. 

Best,

Ghasem

[gashjaei · Accepted solution]

Hello 

Finllay got the answer, 

Sever has a issue, change the server os and now works fine. 

tnx