I just setup a new Balance 20 router (5.4.9 b1732) for a small remote office, with two Cisco SG300-10 managed switches (latest fw, 188.8.131.52) connected to the Balance 20 LAN ports (1 and 2).
I could not get a L1 physical link with the router and switches in their default configurations. I did not have crossover cables, but the switch (if not the Balance also) supports auto MDI/MDIX so that should not have been an issue. I also disabled STP in the Cisco switches. After no link, I initially forced the port on the Cisco switch to 100M and was able to get a link light and connectivity, but after testing (and very slow internet speeds) determined that the switch was reporting a high level of packets with errors. I tried forcing various duplex, MDI/MDIX, and auto advertisement settings on the Cisco port side but could not clear up the packets with errors.
I reset the Cisco port configuration to default (auto everything), and forced the Balance 20 LAN interface speed to 100M full duplex (advertise speed enabled), and finally was able to get a solid link without errors (though only 100M).
Is anyone aware of gigabit auto negotiation issues with Cisco switches and Balance routers? Are there certain settings required on the Cisco side to work with the Balance 20? I was working with one switch at a time before having success with the Balance 20 forced to 100M, so I don’t think it’s a defective switch (unless I got two bad ones).