Internet Connectivity Problem with FortiVM

[DionisisK]

Hello team,

I'm facing a strange issue with a FortiVM we have deployed on our company.

Every 2 or 3 hours, we are losing Internet connectivity. Tried to ping from Forti CLI to 1.1.1.1 / 8.8.8.8, I'm getting no reply, tried to ping google.com or any other web page and I'm able to resolve those URLs to their relevant Public IPs (but no reply), so there is no DNS issue.

We've tried to transfer this VM to a different ESXi, but the issue wasn't resolved.

Yesterday, we re-deployed the FortiVM (fresh install, not a snapshot from the old VM) with TAC support, upgraded to 7.2.12, but today, in my surprise, we had the exact same issue.

We are using this firewall for SSL-VPN Connections, no web filtering or any other "extreme" security features are enabled.

The firewall has two Virtual Interfaces (one internal, one external) which are connected to the ESXi through a trunk interface.

Anyone had this issue before?

Thanks in advance. 

[sjoshi]

Hi DionisisK,

Can you share below output.

get sys arp

get router info routing-table all

Ping 1.1.1.1 and take below sniffer

diag sniff packet any 'host 1.1.1.1 and icmp' 4 0 l

[DionisisK · Accepted solution]

Issue resolved. Seems that another turned off VM had the same IP.

[maroond]

Interesting problem! Have you checked the FortiVM's ARP table during the outage? Also, examine the routing table closely; a rogue entry might be the culprit. Could also be a resource issue on the ESXi host impacting network performance. Try simplified rule sets, similar to solving a puzzle like Block Blast , to isolate the cause.

[DionisisK]

I've check both but nothing seemed wrong. My guess is that something was wrong with the ESXi and his ARP table probably. Not familiar with system part but changing the Public IP resolved the issue.