Example Of Subnet Routing - HP GbE2c - Blc Layer 2/3 Fiber SFP Option Application Manual

Take a closer look at the GbE2c in the following configuration example:
Figure 15 Switch-based routing topology
The GbE2c connects the Gigabit Ethernet and Fast Ethernet trunks from various switched subnets throughout one
building. Common servers are placed on another subnet attached to the switch. Primary and backup routers 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 switch, 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.
To make implementation even easier, UDP Jumbo frame traffic is automatically fragmented to regular Ethernet frame
sizes when routing to non-Jumbo frame VLANS or subnets. This automatic frame conversion allows servers to
communicate using Jumbo frames, all transparently to the user.

Example of subnet routing

Prior to configuring, you must be connected to the switch Command Line Interface (CLI) as the administrator.
NOTE: For details about accessing and using any of the menu commands described in this example, see the
HP c-Class GbE2c Ethernet Blade Switch Command Reference Guide.
1. Assign an IP address (or document the existing one) for each router and client workstation.
In the example topology, the following IP addresses are used:
Table 021 Subnet routing example: IP address assignments
Subnet
1
2
3
4
Devices
Primary and Secondary Default Routers
First Floor Client Workstations
Second Floor Client Workstations
Common Servers
IP Addresses
205.21.17.1 and 205.21.17.2
100.20.10.2-254
131.15.15.2-254
206.30.15.2-254
Basic IP routing 89