lag hash

Configures LAG and Layer 3 ECMP hashing parameters such as where to start picking headers for key generation, the number of headers to be considered, and so forth.

Syntax

lag hash { bos | hdr-count | hdr-start | normalize | pwctrlword | rotate | speculate-mpls | srcport }
lag hash bos { skip | start }
lag hash hdr-count count
lag hash hdr-start { fwd | term }
lag hash normalize
lag hash pwctrlword
lag hash rotate rotate-number
lag hash speculate-mpls { enable | inner-eth | inner-ip-raw | inner-ip-tag | inner-ipv6-raw | inner-ipv6-tag }
lag hash srcport
no lag hash bos
no lag hash hdr-count
no lag hash hdr-start
no lag hash normalize
no lag hash pwctrlword
no lag hash rotate
no lag hash speculate-mpls
no lag hash srcport

Parameters

bos
Ignore the entire MPLS label stack and use only the BOS label for hashing.
skip
Hash from the label following the BOS label.
start
(Default) Start the hash from the BOS label.
hdr-count count
Configures the number of headers to be considered for LAG hashing. Values range from 1 through 3. The default is 3.
hdr-start
Specifies where to start picking headers for the key generation.
fwd
(Default) Start from the inner header, which is used for forwarding the packet.
term
Start from the outer header, which is the header below the forwarding header and is the last terminated header.
normalize
Configures using the same hash in both directions. The default is disabled.
pwctrlword
Include the PW control word in hashing. The default is disabled.
rotate rotate-number
Configures hashing randomness. Values range from 0 through 15. The default is 3.
speculate-mpls
Enable MPLS speculate or Ethernet/IP.
enable
Enable Speculative MPLS.
inner-eth
Enable inner Ethernet header hash for L2VPN.
inner-ip-raw
Enable inner IPv4 header hash for L2VPN raw mode.
inner-ip-tag
Enable inner IPv4 header hash for L2VPN tag mode
inner-ipv6-raw
Enable inner IPv6 header hash for L2VPN raw mode
inner-ipv6-tag
Enable inner IPv6 header hash for L2VPN tag mode
srcport
Includes the source port in the hashing configuration. The default is not to include it.

Modes

Global configuration mode

Usage Guidelines

To restore default settings, use the no forms of these commands.

Table 1. Support Matrix
Command Supported In Not Supported In
lag hash bos
  • SLX 9540
  • SLX 9640
All other platforms
lag hash hdr-count
  • SLX 9150
  • SLX 9250
  • SLX 9540
  • SLX 9640
  • Extreme 8520
  • Extreme 8720
  • SLX 9740
  • Extreme 8820
lag hash hdr-start
  • All platforms
 None
lag hash normalize
  • SLX 9540
  • SLX 9640
  • SLX 9740
  • Extreme 8820
All other platforms
lag hash pwctrlword
  • SLX 9540
  • SLX 9640
All other platforms
lag hash rotate
  • SLX 9540
  • SLX 9640
  • SLX 9740
  • Extreme 8820
All other platforms
lag hash speculate-mpls
  • SLX 9540
  • SLX 9640
All other platforms
lag hash srcport
  • SLX 9150
  • SLX 9250
  • SLX 9540
  • SLX 9640
  • Extreme 8520
  • Extreme 8720
  • SLX 9740
  • Extreme 8820

Examples

The following example changes the hdr-count value to 2.

device# configure terminal
device(config)# lag hash hdr-count 2

The following example changes the hdr-start value to term.

device# configure terminal
device(config)# lag hash hdr-start term

This following example is the output of the allowed configuration on an Extreme 8820 device. 

SLX (config)# # lag hash ?
Possible completions:
 normalize  Enable/Disable using the same hash in both directions of a flow
 rotate   Hash Rotate
SLX (config)#
9038943-00 Rev AA