Limitations on trident3

Limitation1:double 'pop_vlan' actions in flow entry on trident3 chip.

delete inner and outer tags in vcap, icap does not match any vlan tag.So may mismatch other packets in icap at this time.

Example:

Add a flow with double ‘pop_vlan’:

ovs-ofctl add-flow br0 in_port=1,dl_vlan=200,actions=pop_vlan,pop_vlan,output:2

send packets

send packets with outer vlan is 200,inner vlan is 100,then this kinds of packets can be transmitted correctly after pop these two vlans.Send others packets which outer vlan is not 200 or untag packets to port 1,then all the packets may be transmitted by port 2.But theoretically,the packets should not match the above flow.

Limitation2:TD3(s5248,as7326_56x,7726) and Tomahawk don't support egress-meter.

Limitation3:tcam usage

TD3 platforms icap entries max limitation is 3k, even if enable match-mode, the value is still 3k.

Limitation4:Trident3 does not support ingress-rate-limit.

Limitations5:Pop mpls

1) pop one mpls label,match fields exist only one mpls_label.

send packets with only one mpls label,then in SDK match mpls label finally.

2) pop one mpls label,match fields exist two mpls_labels.

send packets with two mpls labels(label1,label2),then in SDK match mpls label1 finally.

3) pop two mpls labels,match fields exist two mpls_labels.then in SDK match mpls label2 finally.