Force10 Networks PSeries 100-00055-01 User Manual
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Command Line Interface
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:
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
:
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
root@# pnic macrewrite-on 0
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 ~]#
MAC Rewrite Enabled
LSB Rewritten for Entered Index
MAC Rewrite Enabled
Rewriting Destination MAC Addresses to Load Balance
Step
Task
1
Enter the command
pnic macrewrite-on 0 channel to enable MAC rewriting.
2
Verify that MAC rewrite is enabled using the command
pnic showconf.