this is customer network topo, when customer ping server address 172.28.127.78 from pc address 172.18.222.52, found there is packet loss from time to time.
#Oct 26 2017 08:56:32+08:00 S9303-1 L2IFPPI/4/MFLPVLANALARM:OID 220.127.116.11.4.1.2011.5.25.160.3.7 MAC move detected, VlanId = 975, MacAddress = 0000-5e00-014b, Original-Port = Eth-Trunk1, Flapping port = GE2/1/7. Please check the network accessed to flapping port.
1. according to customer feedback topo, we have checked that haven't found packet loss on ME60,
2. then we deploy traffic statistic on interface Eth-Trunk2 and G2/1/7 of S9303,
3. customer ping 172.28.127.78 from pc with 33 packets, found just pass 18 packets and lost 15 packets,
4. then we checked the traffic statistic on S9303, found 33 packets passed inbound and outbound direction on interface Eth-Trunk2, but on interface G2/1/7, found there is 33 packets passed inbound direction and just 18 packets passed outbound direction, it is same as the result which is on PC ping.
5. we checked on S9303, found there is mac flapping on interface G2/1/7 and Eth-Trunk1
6. we checked with customer, the Eth-Trunk1 connect NE40 device, and there is a same vrid on NE40, so S9303 will learn same mac address from two different interface, so will appear mac flapping
there are two same vrid connect S9303, so S9303 will learn same mac address from two different interface, so will appear mac flapping, so when ping server address from pc will appear packet loss.
modify the vrid value to 175 on ME60 for not same as other device in customer network
ip address 172.28.127.71 255.255.255.240
vrrp vrid 175 virtual-ip 172.28.127.70
vrrp vrid 175 priority 120
vrrp vrid 175 preempt-mode timer delay 1200
vrrp vrid 175 track interface GigabitEthernet1/0/9 reduced 50