If you are using the current version of Cumulus Linux, the content on this page may not be up to date. The current version of the documentation is available here. If you are redirected to the main page of the user guide, then this page may have been renamed; please search for it there.

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.

The values provided in the profiles below are the maximum values that Cumulus Linux software allocates; the theoretical hardware limits might be higher. These limits refer to values that have been validated as part of the unidimensional scale validation. If you try to achieve maximum scalability with multiple features enabled, results might differ from the values listed in this guide.

Spectrum

Profile
MAC Addresses
Layer 3 Neighbors
Longest Prefix Match (LPM)
default 40k 32k (IPv4) and 16k (IPv6) 64k (IPv4) and 28k (IPv6-long)
l2-heavy 88k 48k (IPv4) and 40k (IPv6) 8k (IPv4) and 8k (IPv6-long)
l2-heavy-1 180K 8k (IPv4) and 8k (IPv6) 8k (IPv4) and 8k (IPv6-long)
v4-lpm-heavy 8k 8k (IPv4) and 16k (IPv6) 80k (IPv4) and 16k (IPv6-long)
v4-lpm-heavy-1 8k 8k (IPv4) and 2k (IPv6) 176k (IPv4) and 2k (IPv6-long)
v6-lpm-heavy 40k 8k (IPv4) and 40k (IPv6) 8k (IPv4), 32k (IPv6-long) and 32K (IPv6/64)
lpm-balanced 8k 8k (IPv4) and 8k (IPv6) 60k (IPv4), 60k (IPv6-long) and 120k (IPv6/64)

Spectrum-2 and Spectrum-3

Profile
MAC Addresses
Layer 3 Neighbors
Longest Prefix Match (LPM)
default 50k 41k (IPv4) and 20k (IPv6) 82k (IPv4), 74k (IPv6-long), 10K (IPv4-Mcast)
l2-heavy 115k 74k (IPv4) and 37k (IPv6) 16k (IPv4), 24k (IPv6-long), 10K (IPv4-Mcast)
l2-heavy-1 239K 16k (IPv4) and 12k (IPv6) 16k (IPv4), 16k (IPv6-long), 10K (IPv4-Mcast)
v4-lpm-heavy 16k 41k (IPv4) and 24k (IPv6) 124k (IPv4), 24k (IPv6-long), 10K (IPv4-Mcast)
v4-lpm-heavy-1 16k 16k (IPv4) and 4k (IPv6) 256k (IPv4), 8k (IPv6-long), 10K (IPv4-Mcast)
v6-lpm-heavy 16k 16k (IPv4) and 62k (IPv6) 16k (IPv4), 99k (IPv6-long), 10K (IPv4-Mcast)
lpm-balanced 16k 16k (IPv4) and 12k (IPv6) 124k (IPv4), 124k (IPv6-long), 10K (IPv4-Mcast)
ipmc-heavy 57k 41k (IPv4) and 20k (IPv6) 82K (IPv4), 66K (IPv6), 8K (IPv4-Mcast)
ipmc-max 41K 41k (IPv4) and 20k (IPv6) 74K (IPv4), 66K (IPv6), 15K (IPv4-Mcast)

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

For the ipmc-max profile, the cl-resource-query command output displays 33K instead of 15K as the maximum number of IPv4 multicast routes in switchd. 15K is the supported and validated value. You can use the higher value of 33K to test higher multicast scale in non-production environments.

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:

Profile Mroute Entries ACL Entries
default 1000 500 (IPv6) or 1000 (IPv4)
ipmc-heavy 8500 1000 (IPv6) or 1500 (IPv4)
acl-heavy 450 2000 (IPv6) or 3500 (IPv4)
ipmc-max 13000 1000 (IPv6) or 2000 (IPv4)

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:

Profile Mroute Entries ACL Entries
default 1000 250 (IPv6) or 500 (IPv4)
ipmc-heavy 8500 500 (IPv6) or 750 (IPv4)
acl-heavy 450 1000 (IPv6) or 1750 (IPv4)
ipmc-max 13000 500 (IPv6) or 1000 (IPv4)