A small LAN whose gateway is a five port router has a workstation connected like so,
Workstation switch router ( rest of the LAN )
I add another switch, i.e.
Workstation new switch switch router
The workstation is now almost cut off - ping packets are dropped and web pages start to load slowly then freeze. I try different cables. It is an auto-sensing switch so misuse of the uplink port or its neighbor is not the issue (which would in any case cause no connectivity, not poor connectivity?). Replacing the cable between the switches does not help.
I try another switch in place of the new switch with the same result, some but poor connectivity.
If the new switch is connected directly to the router it works fine. All the switches involved are consumer-grade 10/100 5-port. Assuming no misuse of ports nor bad cables, what could be the trouble?