Have you seen interfaces going up and down every 3 seconds?
Hi All,
Has anyone seen interfaces go up/down every 3-5 seconds?
This is a CRS125 with Mikrotik RBcAP2n Access Points attached:
Just started happening after upgrade to 6.39.2 however occurs on firmware 6.38.7 (bugfix) too.
If you can not easily replace the cable, try manually setting the speed on each end.
I’ve seen them many times in my 35 years of networking. It is most often the cable, but I have also seen interfaces fail after a power cycle. Most recently, I had this happen on a CCR1009. The interface was constantly going up and down. The machine (an ultrasound machine) worked okay on a Cisco switch, but began having issues attached to the CCR shortly after a power outage. In this case, it was not the cable - the interface in the machine was no longer able to keep a stable link. I fixed it by hacking the machine (a windows 7 based os) and attaching an external USB ethernet interface.
I haven’t tried pinning the ports to 100MBit/full on BOTH sides - should have given that a try. I just tried the CRS side.
I haven’t seen failures after reboot as a pattern but I will start to look for that.
Youse Cable Test Equipment!
disable autoneg.. may solve the problem