On Ethernet ports of the NE40 router it can be noticed that ports through which traffic is not flowing for long time are going down and very fast up afterwards.
%Jun 22 01:30:06 2007 WAWRT2 IFNET/5/UPDOWN:Interface Eth-Trunk0 Turns into DOWN state
%Jun 22 01:30:06 2007 WAWRT2 L2IF/5/L2IF UPDOWN:Switch Port[Eth-Trunk0] state changed to DOWN.
%Jun 22 01:30:06 2007 WAWRT2 IFNET/5/UPDOWN:Interface Ethernet3/1/15 Turns into DOWN state
#Jun 22 01:30:06 2007 WAWRT2 SRM/5/TRAP:184.108.40.206.4.1.2011.5.25.37.2.114 Interface 201328770 Turns into Physical Up state
#Jun 22 01:30:06 2007 WAWRT2 IFNET/5/TRAP:220.127.116.11.18.104.22.168.5.4 Interface 201328770 Turns into Up state
#Jun 22 01:30:06 2007 WAWRT2 IFNET/5/TRAP:22.214.171.124.126.96.36.199.5.4 Interface 2310 Turns into Up state
%Dec 9 11:08:35 2006 WAWRT2 SRM/6/general log: IFM find port 3/0/2 has no input packets for 1 time(s)
This mechanism is enabled by default and can be disabled with the following command under interface view:
undo port-self-protect enable.
However it is suggested to not disable this functionality as such mechanism can be very useful on ports and connections which are used as back-ups and normally there is no traffic flowing through them. To make these tests happen less frequently testing interval can by changed by the command:
port-self-protect timer interval
Due to the lack of traffic on Ethernet interface for a specified period of time NE40 performs port test in order to check whether port on which no traffic has been received in working properly.
This is normal behavior for NE40 Ethernet ports which are not receiving any traffic for some period of time. If such functionality is not desired it can e turned off (which is not recommended) or longer time can be specified.