2votes
1comment
51views
New Extreme 5420M-24 fibre uplink transmits but never receives: the two ends were forced to different speeds
Replacing an old Dell switch with an Extreme 5420M-24, the same SFP module that had worked in the Dell would not bring the network up: the uplink port was active with rising TX counters but RX stayed at zero, no DHCP address, no ping to the firewall, and a new SFP+ module behaved the same. Ethernet…
