Lenovo ThinkSystem NE2552E, Application Manual

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NE2552E Application Guide for ENOS 8.4
Take a closer look at the NE2552E in the following configuration example:
Figure 34.
Switch ‐ Based Routing Topology
The NE2552E connects the Gigabit Ethernet and Fast Ethernet LAGs from various
switched subnets throughout one building. Common servers are placed on another
subnet attached to the switch. A primary and backup router are attached to the
switch on yet another subnet.
Without Layer 3 IP routing on the switch, cross ‐ subnet communication is relayed
to the default gateway (in this case, the router) for the next level of routing
intelligence. The router fills in the necessary address information and sends the
data back to the switch, which then relays the packet to the proper destination
subnet using Layer 2 switching.
With Layer 3 IP routing in place on the NE2552E, routing between different IP
subnets can be accomplished entirely within the switch. This leaves the routers free
to handle inbound and outbound traffic for this group of subnets.
10 Gbps
10 Gbps
First Floor
10/100 Client Subnet
100.20.10.2-254
Second Floor
10/100 Client Subnet
131.15.15.2-254
Primary Default
Router:
205.21.17.1
Secondary Default
Router:
205.21.17.2
IF#1
IF#2 IF#3
IF#4
Server Subnet:
206.30.15.2-254