We used a switch with 5.6.x for testing. Then tried upgrading to 6.0.x and then downgraded again to verify they started working.
Support has simply been talking around the problem with the standard "unsupported" line. I've been working through my sales team to try to get an answer.
I purchased a ton of new GBICs and they are all useless if we upgrade.
I found a solution to my problem which was connecting a standalone FW-124E to a Cisco 3750X via fiber. It appears in 6.2 there is an issue with the trunking. I removed the trunk setup on the FortiSwitch port in which I installed the GBIC, and just added all VLANs to the Allowed VLANs. Funny thing, the trunking worked when connecting the two switches by RJ45 ports.
I had the same experience. I had a link-light on the SFP port of the FortiSwitch, but not on the Cisco. I resolved this by adding the speed nonegotiation command to the Cisco port config and then changing the Fortinet port config from auto-negotiate to force 1000 full-duplex. After making these adjustments, the Cisco link-light was on and the port status showed up/up (before it was down/down), but there was still no traffic.
One other strange thing, although I could not pass traffic in the conventional sense, the Tx and Rx counters for both devices showed some packets were being transferred and that one device's Rx count matched the other's Tx count, and vice versa.
Also, the forwarding table on my Fortinet contained the MAC addresses of devices connected to all of my VLANs on the Cisco side. The Cisco switch I have been using is a production switch in my server room.
Perhaps I have raised more questions than answers. I have a current ticket open with Fortinet on my issue and I'm not letting go until I know what is going on. I will post again if I get anywhere.
For the sake of being complete and for any lurkers or future Fortinet customers, the Fortinet engineer assigned to my case blamed the problem on an unsupported GBIC. He referred me to the list of compatible GBICS published by Fortinet and recommended I purchase one. I did. The problem still exists with the approved GBIC. When I discovered the workaround, see my post above, it was working from a Fortinet approved GBIC. For kicks, I put in the original GBIC and it functions equally well.
please i have the same issue with the same situation, i have Fortiswitch 124E connected via fiber to cisco 3750 after adding the command speed nonegotiate the link be UP/UP but still no traffic between the two switch. how can i solve this issue please ?
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