linino yun ethernet link down after 20-30 min

Hello,

On my linino yun , why the Ethernet link down after few minutes .

when the linino is ok :

root@linino:~# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default r8-r-rhpzm-1-pu 0.0.0.0 UG 10 0 0 eth1
128.141.161.0 * 255.255.255.0 U 10 0 0 eth1
192.168.240.0 * 255.255.255.0 U 0 0 0 wlan0

and after 20-30 min , under terminal i can see :

root@arduino:/# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
128.141.161.0 * 255.255.255.0 U 10 0 0 eth1
root@arduino:/#
root@arduino:/#

I can restart the network (under terminal ) :

/etc/init.d/network restart
[ 3328.510000] eth1: link down
[ 3330.370000] eth1: link up (100Mbps/Full duplex)

this is my linino yun :
root@linino:~# /usr/bin/lininoio -v
DISTRIB_ID="Linino"
DISTRIB_REVISION="223d5a8"
BUILD_DATE="2016-06-01"

can you help me , anybody have the same problem ?

On my arduino yun , i dont have this problem , but just on linino board.

Cheers

Emmanuel