In mobile bear network NE80E connect to Softswitch MSC server,MGW and run MSTP,when one ethernet port up and change to forwarding mode by connecting to a laptop, there are 2-3 ping packets loss to MSC server and MGW,the service will disconnect in these 2-3 seconds.
Ping MSC and MGW there are 2-3 packets loss.There are SCTP disconnection and fluctuation alarm.
After configure" stp converge normal",the problem solved.
When port change to forwarding mode, it will send TC(topology change)packet. By default NE80E stp converge mode is fast, it will cause ARP table refresh when receive TC packet.
The following is the details.
By default, the converging mode of the STP is fast.
fast: deletes ARP entries directly.
normal: ages ARP entries fast.
After the topology of a spanning tree instance changes, the forwarding path of VLANs that are mapped to this instance also changes. So do the ARP entries related with the VLANs. In this case, a switch processes the ARP entries in different ways depending on the STP converging mode.
In the fast mode, a switch deletes the related ARP entries directly.
In the normal mode, a switch sets the EXPIRE time of the ARP entries to zero and then ages them. If the detect times of the ARP entry is greater than zero, the switch detects the ARP entry before it deletes the entry.
Configure "stp converge normal" in NE80E when it runs MSTP.