Optimal connections for connecting 2 SG300-28 switches to a Cisco 1921 router

[Pderby]

My network equipment sits in a home office environment.  I just replaced a Cisco Catalyst 3750-48G switch with two SG300-28 switches to eliminate the fan noise. The router between the LAN and WAN is a Cisco 1921. What is the optimal way to connect these 3 network devices?  Daisy chain the router to switch "B" and switch "B" to switch "A", or plug both switches into ports on the router?

The Wan side of the router connects to Verizon FIOS.  The LAN side of the router is currently connected to SG300-28 switch "A".  Switches "A" and "B" are connected with an optical cable.  The switches handle two networks, the LAN is untagged VLAN 1 and the WAN is VLAN 2 with two tagged interfaces to support connections to two MacMini servers.  The Mac mini only has one Ethernet NIC, so the two Mac Minis are configured to use VLAN 2  .1q tagged connections so the minis can talk to both the LAN and the WAN via the single ethernet NIC on each server.  VLAN 2 is only on Switch "B".  The WAN VLAN interfaces handle traffic from FIOS to the router, one of the minis that takes care of email,  the other Mini that hosts a web site and the remaining untagged WAN interface is used by a media server.

The router has 4 additional Gig-E interfaces in the "slot"  that are pooled using BVI and part of the LAN configuration.  DHCP is handled by the router.  DNS is handled by the Mac Minis.  

An Ooma VOIP ATA is connected directly to one of the LAN ports on the router.

Ideas for how  to configure this setup for optimal performance would be welcomed!

[chrebert]

Hello Paul,

I don't quite understand how the WAN can be on one side of the router, but then the switches that are on the LAN side also pass along a WAN VLAN.  I may simply be missing something here, but I think my suggestion will make sense anyway.  If they don't please post a diagram so I understand your setup a bit better.

To me the optimal way to configure this setup would be both switches connected to the router, to avoid the need for clients connected to the second switch to travel through the first switch.  

However these switches will move traffic at wire speed if it is in the same VLAN, and will route at wire speed as well, so there will be very little difference in speed based on how you hook them up.

Your best bet would be to try out both setups and see which one works best, but I'm pretty sure you won't notice much of a difference.  

Hope that helps and thank you for choosing Cisco,

Christopher Ebert - Advanced Network Support Engineer

Cisco Small Business Support Center

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