Hi,
I have a 6509-E that is getting tons of transmit discards on two non-fabric enabled line cards. This is only impacting some video traffic. I have a 720 supervisor engine in slot 5. Slot 5 comes up as the only active fabric slot under the "show fabric active" command. When I do the show fabric switching mode command, slot 5 says "bus". So I'm confused on whether that is utilizing the switching fabric or not. Slot 6 has a " WS-X6724-SFP" which I understand is a fabric enabled card. What I did is moved the heavy video traffic ports to slot 6. When I utilize strictly ports on slot 6 between the sending and receiving access switches for the video source and destination, I get a lot more transmit discard errors than if I were using a combination of slot 3 and 6 (etherchannel) connections between the same access switches. So my questions are:
1.) Is truncated mode the best mode to go between non-fabric and fabric enable cards?
2.) Is the supervisor slot (5) reading "bus" as switching mode normal?
I've been trying to mitigate these transmit discards for months now and I am at the end of my rope. I went with the line being oversubscribed and have tried many different solutions with little progress. Using an etherchannel (slot 3 and 6) down to the receiving access switch has lessened the transmit discards but not eliminated them. All the discards in this configuration occur on 3/4 and none occur on 6/11. If I removed 3/4 from the etherchannel the 6/11 will gain more errors more frequently than the etherchannel, and that is with the source being on slot 6 as well. Kind of at the end of my rope.
show fabric switching-mode
Global switching mode is Truncated
dCEF mode is not enforced for system to operate
Fabric module is not required for system to operate
Modules are allowed to operate in bus mode
Truncated mode is allowed, due to presence of CEF720 module
Module Slot Switching Mode
2 Crossbar
3 Bus (WS-X6148A-GE-TX)
4 Bus (WS-X6148A-GE-TX)
5 Bus (supervisor 720)
6 Crossbar (WS-X6724-SFP)
8 Crossbar
9 Crossbar
