I have an R500 that occasionally drops traffic for periods of about 5 seconds at a time. This happens maybe a couple times a day, but it's quite noticeable when I'm streaming music and it just drops out.
The key bits in the log are as follows:
Mar 13 18:02:19 R500 user.warn kernel: Enet:0 port:4 down Mar 13 18:02:19 R500 user.warn kernel: 955x_GMAC: unit 0: phy 4 not up carrier 1 Mar 13 18:02:19 R500 user.info kernel: br0: port 1(eth0) entering disabled state (events/0,5) Mar 13 18:02:21 R500 user.warn kernel: Enet:0 port4 up Mar 13 18:02:21 R500 user.warn kernel: 955x_GMAC: enet unit:0 is up... Mar 13 18:02:21 R500 user.warn kernel: eth0 RGMII 1000Mbps full duplex
You can see that the port comes back up almost immediately after going down, but during that time it basically doesn't work. I'd thought there might be an issue with the PoE switch or the ethernet cable, but I've tried a different switch and a different cable and I still see the issue. And it stays powered the entire time, it's not like there's an issue with power delivery.
The R500 is running latest firmware, 126.96.36.199.432.