Force10 Networks 100-00055-01 manual Rewriting Destination MAC Addresses to Load Balance

LSB Rewritten for Entered Index

MAC Rewrite Enabled

This feature can be enabled per channel. When MAC rewrite is enabled, the P10 appliance classifies the incoming traffic into one of 256 hash buckets to determine the value to be written to the LSB of destination MAC address. A hash function based on the source and destination IP addresses is used to calculate an

8-bit index for each incoming packet. The index is used to look up the LSB values to be written into the packet.

To enable MAC rewriting:

Step Task

1Enter the command pnic macrewrite-on 0 channel to enable MAC rewriting.

2Verify that MAC rewrite is enabled using the command pnic showconf.

Two additional commands are available with this feature:

•pnic updatemacvalue—Assigns a new LSB for a particular index.

•pnic getmachasindex—Obtains the hash index value for a particular source and destination IP combination.

In Figure 34:

1.MAC rewriting is enabled

2.The user associates an LSB value with a particular index value.

3.All packets with source and destination IP addresses that hash to this index value then have the the least significant byte of their destination MAC address overwritten with the user-entered LSB value.

Figure 34 Rewriting Destination MAC Addresses to Load Balance

root@# pnic macrewrite-on 0	MAC Rewrite Enabled
No channel number specified. Assuming channel 0

***Enabling MAC rewrite on card:0 channel:0 is successful! [root@localhost ~]# pnic showconf

No device number specified. Assuming device 0

####################### On MASTER FPGA #######################

Temporary Packet Linked-list Limit: unlimited.

Timeout for Flow Garbage Collection: 16 (seconds)

Truncation after Match Packet: full packet.

####################### On PCI FPGA #######################

DMA Burst Size: 1024 (Bytes).

DMA Flush Timer: 1 (ms).

Interrupt Frequency Timer: 1(ms).

DMA Capture: on.

MAC Rewrite state: CH0 - enabled; CH1 - disabled

Version : P_MAIN2.0.0.80 [root@localhost ~]#pnic updatemacvalue

No device number specified. Assuming device 0 Please input the hash index [0-255]: 47

The value to replace: 69

The MAC updating is done on register 0x4bc - index:47!. [root@localhost ~]#

52 Command Line Interface