Hi Rushi,
I tried your solution at Ex4550 end for the following setup and it didn' t work out and I need your assistance.
For the original setup, Fortigate< Port Channel-> Cisco 3850 Stack Switch (Core) < Port Channel-> Cisco 3650 Stack Switch (Access), the fortigate is on Layer 3 (router on the stick mode with subinterface for each vlan) , two set of Cisco stack switches are all running layer 2. The interconnection is running port channel and it works fine.
Recently we plan to upgrade the Cisco 3850 Stack switch (core) to Juniper 4550, before we replace the Cisco 3850 stack switch (core) , we did the following sceneario for POC.
The original setup is unchange so that the production is on going, we connect 2xJuniper Ex 4550 running VSS to Cisco 3850 Stack Switch (core) using SFP+, connect a spare Cisco 3850 switch (access) to Juniper EX4550 on SFP+, connect a pc to the sapre cisco 3850 switch. The links between them are configured as LAG/port channel.
At Cisco end, the port channel is up on both Cisco 3850 stack switch (core) and the spare Cisco 3850 (access), however the PC connects to the switch port is not able to have the ip from fortigate. We also replace RSTP with VSTP in Juniper without luck.
It is a simple setup in both Cisco and Juniper however we are not able to identify the root cause. Can you shed some light?
Thanks
Qing
<-> Juniper Ex 4550 (Vss) <-> Cisco 3850 Swich (Spare one)