Switch Router – Understanding Switch Speed and Router Speed

1. Yes, it is possible.

2. You are doing something wrong, most likely tagging frames on the router but the trunk has VLAN 1 as native.

To confirm what your trunking settings are use:

show interfaces trunk

I like to keep the subinterface IDs matching the VLAN number although it is not required. Use a configuration like:

! Switch
! Port to Laptop
interface Fax/x
switchport mode access
switchport access vlan 1
spanning-tree portfast
description Port to PC
! Port to Netgear
interface Fax/x
switchport mode access
switchport access vlan 1
spanning-tree portfast
description Port to Netgear
! Port to Cisco router
interface Fax/x
switchport trunk encapsulation dot1q
switchport mode trunk
spanning-tree portfast trunk
description port to Cisco router

For the router:

! Router
! Port to switch
interface E0/0.1
encapsulation dot1q 1 native
ip add 192.168.0.70 255.255.255.0
description VLAN1 to Netgear
interface E0/0.10
encapsulation dot1q 10
ip add 192.168.10.70 255.255.255.0
description VLAN10
interface E0/0.20
encapsulation dot1q 20
ip add 192.168.20.70 255.255.255.0
description VLAN20
ip routing
ip route 0.0.0.0 0.0.0.0 192.168.0.1

Obviously replace IP with your desired IP in the subnet.

Will the computers be able to connect to the NAS at 10GbE?

Yes, if both the computers and the NAS are connected to the switch at 10GbE and do not require routing (ie. both are in the same subnet and VLAN).

Will the router slow things (other than internet) down?

It will slow anything which passes through it down to gigabit, but only if is faster to begin with.

Any other drawbacks?

This could be the perfect setup for you, but it could also fail to deliver under certain conditions. Since we don't know what it has to deliver, it's hard to tell. It all depends on how you will use it and what you expect from it...