Configuring LAG Hashing
To configure symmetric LAG hashing on supported devices, complete the following
tasks.
- Define where to start picking headers for the key
generation, using the lag hash
hdr-start command.
- fwd - Start from the header that is used for the forwarding
of the packet (inner header). This is the default option.
- term - Start from the last terminated header (outer
header) - the header after the forwarding header. For switching
traffic, as there is no header below the forwarding header, hashing
is not visible.
- Configure the number of headers to be considered
for LAG hashing, using the lag hash
hdr-count command. The default value is 1. There can be a
maximum of 3 headers - based on the first header selected using the command in
the previous step.
The following options provide other LAG configurations to achieve
specific tasks:
- Configure hash rotate using the lag hash rotate
command to provide different options for randomness of hashing. The number can
be between 0 and 15. The default value is 3.
- If there is a need to use the same hash in both directions, configure
hash as normalize, using the lag hash normalize command.
The normalize option is disabled by default.
- Allow the source port to be included in the hashing configuration
using the lag hash srcport command. The source port is
not used for hashing by default.
To skip the entire MPLS label stack and pick only the BOS label for
hashing, use the lag hash bos. By default, if the MPLS
header is used for hashing, all labels, including BOS, are
also used for hashing.
- start - start from BOS. This is the default option.
- skip - hash from header next to the BOS label.
-
Enter the lag hash pwctrlword
command to skip the password control word in the hashing configuration.
The following MPLS transit node LSR hashing configuration options are
available when using the lag hash speculate-mpls
command. The default option is using the MPLS labels.
- enable - Enables Speculative MPLS.
- inner-eth - Enables inner ethernet header hash for L2VPN.
- inner-ip-raw - Enables inner IPv4 header hash for L2VPN raw mode.
- inner-ip-tag - Enables inner IPv4 header hash for L2VPN tag mode.
- inner-ipv6-raw - Enables inner IPv6 header hash for L2VPN raw mode.
- inner-ipv6-tag - Enables inner IPv6 header hash for L2VPN tag mode.
- Enter the lag hash rotate command to specify hashing randomness.
A randomness value ranges from 0 to 15 with a default of 3.
