Supported Route Table Entries

Cumulus Linux advertises the maximum number of route table entries supported on the switch, including:

• Layer 3 IPv4 LPM (longest prefix match) entries that have a mask less than /32
• Layer 3 IPv6 LPM entries that have a mask of /64 or less
• Layer 3 IPv6 LPM entries that have a mask greater than /64
• Layer 3 IPv4 neighbor (or host) entries that are the next hops seen in ip neighbor
• Layer 3 IPv6 neighbor entries that are the next hops seen in ip -6 neighbor
• ECMP next hops, which are IP address entries in the routing table that specify the next closest or most optimal router in its routing path
• MAC addresses

To determine the current table sizes on a switch, use cl-resource-query.

Supported Route Entries

Cumulus Linux provides several generalized profiles, described below. These profiles work only with layer 2 and layer 3 unicast forwarding.

The following tables list the number of MAC addresses, layer 3 neighbors, and LPM routes validated for each forwarding table profile. If you do not specify any profiles as described below, the switch uses the default values.

Spectrum

Spectrum-2 and Spectrum-3

The IPv6 number corresponds to the /64 IPv6 prefix. The /128 IPv6 prefix number is half of the /64 IPv6 prefix number.

Forwarding Resource Profiles

You can configure forwarding resource allocation. Choose the profile that best suits your network architecture.

Spectrum, Spectrum-2 and Spectrum-3

Specify the profile you want to use with the forwarding_table.profile variable in the /etc/cumulus/datapath/traffic.conf file. The following example specifies ipmc-max:

cumulus@switch:~$ sudo cat /etc/cumulus/datapath/traffic.conf
# Specify the forwarding table resource allocation profile, applicable
# only on platforms that support universal forwarding resources.
#
# /usr/cumulus/sbin/cl-resource-query reports the allocated table sizes
# based on the profile setting.
#
#   Values: one of { *** Common ***
#                   'default', 'l2-heavy', 'l2-heavy-1', 'l2-heavy-2',
#                   'v4-lpm-heavy', 'v4-lpm-heavy-1', 'v6-lpm-heavy',
#                   'rash-v4-lpm-heavy', 'rash-custom-profile1',
#                   'rash-custom-profile2', 'lpm-balanced'
#
#                   *** Mellanox Spectrum2+ only platforms ***
#                   'ipmc-heavy', 'ipmc-max'
#
#                   }
#
#   Default value: 'default'
#   Notes: some devices may support more modes, please consult user
#          guide for more details
#
forwarding_table.profile = ipmc-max

After you specify a different profile, restart switchd for the change to take effect.

TCAM Profiles - Spectrum Only

Specify the profile you want to use with the tcam_resource.profile variable in the /etc/mlx/datapath/tcam_profile.conf file. The following example specifies ipmc-max:

cumulus@switch:~$ cat /etc/mlx/datapath/tcam_profile.conf
#
# Default tcam_profile configuration for Mellanox Spectrum chip
# Copyright (C) 20xx-2021 NVIDIA Corporation. ALL RIGHTS RESERVED.
#

#TCAM resource forwarding profile
# Applicable for Spectrum-1 and Spectrum-A1 switches only
# Valid profiles -
#    default, ipmc-heavy, acl-heavy, ipmc-max, ip-acl-heavy
tcam_resource.profile = ipmc-max

After you specify a different profile, restart switchd for the change to take effect.

When you enable nonatomic updates (acl.non_atomic_update_mode is TRUE in the /etc/cumulus/switchd.conf file), the maximum number of mroute and ACL entries for each profile are:

When you disable nonatomic updates (acl.non_atomic_update_mode is FALSE in the /etc/cumulus/switchd.conf file), the maximum number of mroute and ACL entries for each profile are: