Description

LACP flapped and network control queue drop is seen.

Symptoms

Egress queues: 8 supported, 7 in use

Queue counters: Queued packets Transmitted packets Dropped packets

0 765954441056 765954441056 0

1 1509494938074 1509323356184 171581890

2 6642156111 6642152436 3675

3 1986872220 1986872220 0

4 55763551856 55763540957 10899

5 22080604615 22080604180 435

6 23530441667 23529084053 1357614 <<<<<< Queue 6 - Network Control queue packet drop due to abnormal inbound traffic

Queue number: Mapped forwarding classes

0 FC-SCAVENGE

1 FC-STANDARD

2 FC-BUSINESS

3 FC-INTERACTIVE

4 FC-VIDEO

5 FC-VOICE

6 FC-NETWORKCONTROL

Solution

Based on the customer description, the LACP flapping was triggered by abnormal spike of the traffic, JTAC did see there were packets dropped (1393642) in the network control queue, it may affect the network performance, and even cause LACP protocol flapping during the severe condition.

 

The customer will apply the policer in the customer interface to limit the inbound traffic:

show configuration firewall policer Megaport_peer

if-exceeding-pps {

   pps-limit 100k;

   packet-burst 100k;

}

then discard;

 

JTAC also suggest the customer to try:

=========================

1) LACP slow mode (30 seconds period)

2) inline mode

3) central mode

LACP has two additional modes: centralize (force RE to process LACP packets) or inline (force PFE to do the transmission).

 

Modification History

1.0

Related Information

NA