I have a Catalyst 3750 Metro running 12.2(25)EY4 on site A and a 2811 running 12.3(11)T4 on site B. There is an MPLS backbone in between and a GRE tunnel configured from site A to site B. At site B there are several hosts receiving multicast flows from site A.
The multicast flows arrives at site B, but the application running on hosts discards packets because they arrive out of sequence.
I tried to force sequencial trasmission of packets with the command ?tunnel sequence-datagrams?, but multicast packets are still discarded with the same log. Below the configuration of tunnel interface on both sites
The command "tunnel sequence-datagrams" does not order packets for transmission. It rather drops packets that arrive out-of-sequence. You do not want to use this so I suggest that this command is removed from both routers.
To solve the issue, first try to reduce the transmissionrate of your multicast application (by reducing quality or resolution) If this gives an improvement the packets are probably asymetrically load-balanced on the MPLS backbone. In that case, your MPLS provider should make arrangements to solve this issue.
Otherwise, you might need to trace some packets and determine wheter you are having out of sequence packets or not and measure the variation in delay on the MPLS network.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...