Let me try answer this to best of my ability (maybe other people will have different opinions/ideas) : )
1. What would happen if the switch has jumbo frames enabled but the firewall interface is set to default 1500 MTU? Is the firewall going to negotiate or drop the traffic.
Put it this way...the bigger packet size, less amount of packets...the smaller packet size, many more packets going through...I cant say for sure if firewall would drop the traffic in this case, but to me, logically thinking about it anyway, sounds like it would actually try to negotiate. Jumbo frames from what I recall are usually 9000 bytes, though technically its anything bigger than 1500 really. Personally, I would try avoid this scenario at any cost. Are you asking this more in theory or is this a real scenario?
2. What if one side of the firewall/switch (both) have jumbo frames enabled and other side firewall/switch (both) are on standard 1500 MTU. Any issues expected in this setup?
I cant say for sure what would happen here, but sounds like the amount of traffic received on both sides would vary significantly based on the packet size, so dropped traffic in this situation would not surprise me at all.
I only remember one time when customer in UK had to enable jumbo frames to make some weird traffic issue through CP appliance work, but I believe he later discovered this was due to switch being configured the same way,
Apologies, but those are best answers I can come up with 😞
Andy
