Can't ping my router from a switch...

[catch21]

...but I can from a hub?

 

I've a Cisco RV042G with an IP address of .20 on its LAN interfaces.

 

I've two desktops running Linux with static IP addresses of .80 and .81

 

I've a Cisco 300 switch, out-of-the-box flat plug-and-play configuration.

 

When the two desktops are plugged directly into the router LAN ports they can ping the router and each other.

 

When the two desktops are connected into a hub which then has one connection to a router LAN port they can still ping each other and the router.

 

The odd thing is, when the hub is replaced by the switch the desktops can ping each other but not the router. Hub works, switch doesn't. With the hub I get ongoing routing to the WAN and therefore internet, with the switch I don't.

 

Can anyone shed any light on what might be the configuration problem please?

Edited June 5, 2013 by catch21

[catch21]

Small update: As a flat out-of-the-box switch it does indeed work (must have been late last night). It is when I try to split the ports between two vlans that something must have been mis-configured, although I can't see what it might be.

 

Is there any reason the 300 series switch (in layer 2 mode) might not like to talk to the router?

[FN-GM]

Is the router on the same subnet as the clients?

[Coops1]

On the switch port connected to the router have you allowed both vlans to trunk?

[catch21]

Is the router on the same subnet as the clients?

 

The router itself has two IP addresses, one on the WAN port which is correct for the ethernet it connects to, the one on the LAN ports in the same scheme as the DHCP address range it is giving out, so yes I believe these are OK.

 

On the switch port connected to the router have you allowed both vlans to trunk?

 

I've two patch cables to the router, one for the LAN from one port on VLAN A, and one for the WAN from a switch port on VLAN B.

 

The problem seems to be solved when the two connections go to a physically different switch.

 

I've turned off spanning tree and GVRP.