I am looking for some assistance when i connect a Linksys SLM2008 Managed/POE switch in to the router. I have configured the router to what I need, 2 VLAN with require routing, however 10 seconds after I plug the switch in, the entire network drops connectivity. This had been happily working, for the last 6 months, and has just started to fail. I have tested the switch and all network devices all work fine, including the switch.
I had changed the ports on the switch as it appeared the it was connected via the POE port on the switch, however this had no effect, If I disconnect the router from the switch then it comes back up after a reboot. The switch has DHCP disabled and is also not doing any services as at present I am just using it as switch. There is no Jumbo frames enable on either or any device.
The best so far I can put it down to is that the router has some form of Hardware fault? Is there any thing else that it could be. Also I have tried all 4 LAN ports on the router, and it has the same effect.
I have used a cheap Netgear just a keep things running, (and it was in the boot as a spare) and it had no trouble working with all other device and cascading to the switch.
Thanks in Advance for you replies.