Switches not playing nicely

[Nemesis3]

I recently added a Netgear GS108T Managed Switch into my network setup. I previously had a Netgear GS108 unmanaged Switch in the spot the managed switch is at now. I plan to team a couple nics on at least one PC and on the Netgear ReadyNAS Pro Business hence the need for a managed switch.

As long as I have PC>switch>Router/Firewall>Cable Modem it doesn't matter whether it is the GS108 or the GS108T everything seems to work fine. However PC>GS108T>GS108>Router/Firewall>Cable Modem introduces incredible lag. Is there an inherent flaw in hooking a managed switch into an unmanaged switch?

I have more PDa's, Smartphones, notebooks and PCS not diagrammed as they are currently offline until I get the basics worked out with these devices.

RCA DCM425 CABLE MODEM>SecureComputing/Snaggear SG570 90.0.0.40>Netgear GS108 unmanaged Switch>Netgear GS108T Managed Switch 90.0.0.50>PC 90.0.0.7=problem
RCA DCM425 CABLE MODEM>SecureComputing/Snaggear SG570 90.0.0.40>Netgear GS108 unmanaged Switch>PC 90.0.0.7=works fine
RCA DCM425 CABLE MODEM>SecureComputing/Snaggear SG570 90.0.0.40>Netgear GS108T Managed Switch 90.0.0.50>PC 90.0.0.7=works fine


Example of a PC's static IP setup
IP Address:90.0.0.7
Subnet Mask:255.255.255.0
Default gateway:90.0.0.40
Preferred DNS server:90.0.0.40


Setup of the managed switch
IP Address:90.0.0.50
Subnet Mask:255.255.255.0
Default gateway:90.0.0.40

Here is a Visio layout of my current setup:
http://img813.imageshack.us/img813/9436/drawing1t.jpg

 

[jdabbs]

Since you have a lot of unused devices, checked the managed switch to make sure you haven't introduced a switching loop (ex: a patch cable with both ends connected to the managed switch or more than one path between switches).

Another potential factor is switch misconfiguration. Resetting the switch to default is a quick way to rule that out.

To head off future problems, don't use subnets you don't own. You are behind NAT, but scenarios like these exist to demonstrate the difference between theory and practice.

 

[PKTSNP]

multicast and traffic shaping.

I use the same configuration with the same equipment in a particular network... how interesting.
GS108T > GS108 > Router/Gateway/Firewall > Internet

I have not experienced any speed problems, let me know if you have questions about my configs.

I am considering swapping the position of the switches to effectively manage traffic. Also, I don't want to create a heavy load on any devices. I'm not sure if will make a difference but there's a great deal of mulicast traffic coming through the unmanaged switch (GS108).

Which is best for traffic shaping?

1) Use IGMP snooping and forward multicast traffic from Managed Switch to Unmanaged GS108? (...seems intensive)

2). Keep managed GS108T behind most multicast traffic, and use multicast filtering as needed?

 

[bendsley]

Managed switch or not, it's still a switch to switch connection. Both run MDIX right, so you don't have to use a crossover cable?

Assuming you haven't messed with VLANs (their default should be VLAN 1), then I would do as suggested previously and reset the managed switch to default and go from there just to rule that out.