I have created a Java program which sends packets with DSCP markings from a computer on one subnet to a computer on another subnet. I used Wireshark to verify the packets preserve the DSCP marking from the source to the destination. The source machine sends the packets to a Cisco SG200-50 switch and then the packets get sent to an old Cisco 2811 router which disseminates them to the destination machine. The router has an old IOS that does not support DSCP, so that's why I added the switch. The DSCP markings seem to have no effect and do not place data in the expected queues.
The packets arrive at the destination machine in the same order as they where sent, however this is not what I expected. My packets can have one of 3 DSCP codes (46, 22 or 0) I expected the "46" packets, then the "22" packets and finally the "0" packets. I am definitely a router/switch newbie, but based on the switch administrator's guide it looks like I have everything setup under the Quality of Service heading as it should be.
- My Qos Mode is enabled and my Trust Mode is DSCP.
- All the interfaces/ports, including the two I use (GE2 and GE3) have their QoS state enabled.
- I set the Scheduling Method to WRR for the 4 queues, however whatever I try for Scheduling method doesn't seem to matter.
- I took the Defaults for the DSCP to Queue table.
- In the Bandwidth table I configured an egress shaping rate for the ports (GE2 and GE3). Whatever I do here doesn't matter though.
- I set the Egress shaping for the 4 queues for each port. Queue 4 has the biggest CIR, followed by 3, then 2 and then 1.
At this point my question is basically what am I missing? Am I able to do what I want? Did I forget some other SG200-50 switch configuration option? I appreciate any guidance you can give me to steer me in the right direction so I can solve this annoying problem.
Thanks
