NVIDIA MLNX-OS User Manual
NVIDIA MLNX-OS User Manual
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User Defined Keys

User defined keys (UDKs) allow defining custom byte keys—that is, groups of bytes that can be matched to a predefined point in the packet (an extraction point, e.g. the start of a MAC header, or an IP header)—which is useful when wanting to make a match with a part of the packet which does not have a dedicated key.

The maximum number of UDKs is 4.

An extraction point may be defined for each packet type in a UDK. For each extraction point, an offset (from the beginning of the extraction) is defined.

To be able to modify a UDK after attaching it to an ACL rule, it is first necessary to un-match the UDK from the ACL, and then change the match mode of the UDK to none using the command “no udk match mode”.

Defining a UDK affects the throughput for packets equal or smaller than 128 bytes.

Configuring UDK

To set UDK with ACL on a specific field:

  1. Define new user defined key called ipv4_udk. Run: 

    switch (config) # udk ipv4_udk
switch (config udk ipv4_udk) # exit


  2. Set user defined key ipv4_udk  to match on IPV4 header in offset 4 bytes from start of header. Run:

    switch (config) # udk ipv4_udk extraction point mode l3 packet type ipv4 extraction point start-of-header offset 4


  3. Set the len (in bytes) of the field to match on. Run:

    switch (config) # udk ipv4_udk len 2


  4. Set the user defined key to work with access list. Run:

    switch (config) # udk ipv4_udk match mode acl


  5. Define new access list table called my_acl_table. Run:

    switch (config) # ipv4-udk access-list my_acl_table


  6. Set new rule on the access list table with the previously defined user defined key to match 0x1234. Run:

    switch (config) # ipv4-udk access-list my_acl_table permit ip any any udk ipv4_udk 0x1234


  7. Bind the access list table to an ethernet interface. Run:

    switch (config) # interface ethernet 1/1 ipv4-udk port access-group my_acl_table


UDK Commands

udk


udk <udk-name>
no udk <udk-name> 

Creates user defined key.
The no form of the command deletes user defined key.
Syntax Description

udk-name

String

Default

N/A

Configuration Mode

config

History

3.6.5000 

Example

switch (config)# udk udk_nameswitch (config udk udk_name)#

Related Commands


Notes

Defining UDK affects the throughput for packets equal or smaller than 128 bytes.

match mode


match mode <match-mode>
no match mode 

Configures user defined key match mode.
The no form of the command resets this parameter to its default.

Syntax Description

match-mode

Possible values:

  • acl

  • all

  • ecmp

Default

None

Configuration Mode

config udk

History

3.6.5000

Example

switch (config udk udk_name)# match mode all

Related Commands

udk <udk-name>

Notes


extraction point


extraction point mode <mode> [packet type <type> [extraction point <point> [offset <offset>]]]

Configures user-defined key extraction point mode.

Syntax Description

mode

Possible values:

  • l2

  • l3

  • l4

packet type

Sets user defined key packet type. Possible values:

  • For L2: l2

  • For L3: arp; ipv4; ipv6

  • For L4: udp

extraction point

Sets user defined key extraction point. Possible values for:

  • l2: l2-ether-type; start-of-header

  • arp: start-of-header

  • ipv4; ipv6: start-of-header; start-of-payload

  • udp: start-of-payload

offset

Sets user defined key extraction point offset
Range: 0-126 (even values)

Default

Mode: l3
Default extraction point per packet type:
L2: start-of-header
ARP; IPv4; IPv6: start-of-header
UDP: start-of-payload
Offset: 0

Configuration Mode

config udk

History

3.6.5000

Example

switch (config udk udk_name)# extraction point mode l3 packet type ipv4 extraction point start-of-header offset 2

Related Commands

udk <udk-name>

Notes


len


len <length>

Configures user-defined key length.

Syntax Description

length

Range: 1-4

Default

4

Configuration Mode

config udk

History

3.6.5000

Example

switch (config udk udk_name)# len 4

Related Commands

udk <udk-name>

Notes


show udk


show udk [<udk-name>] 

Displays summary for user-defined keys.

Syntax Description

udk-name

Displays information about specific UDK

Default

N/A

Configuration Mode

Any command mode

History

3.6.5000

Example

switch (config)# show udk

UDK name: udk_nameMatch mode: noneLength: 4Extraction mode: l3IPv4 extraction point: start-of-headerIPv4 offset: 22IPv6 extraction point: start-of-headerIPv6 offset: 0ARP extraction point: start-of-headerARP offset: 0

Related Commands

udk <udk-name>

Notes



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