Unified Load Balancer Configuration and Administration Guide, Release 2026.03

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Unified Load Balancer Configuration and Administration Guide, Release 2026.03

Miscellaneous configurations

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Explains miscellaneous configurations for technical implementation and operations, including how to configure cilium BPF map and enable cilium hubble statistics.



Configure the Cilium BPF map

Use this procedure to edit the BPF map sizes for Cilium by entering the appropriate CLI commands.

You do not need to configure all map sizes; adjust them as needed for your setup. By default, this CLI does not set any values, so Cilium BPF map sizes will follow Cilium's standards. After committing changes in this CLI, the Cilium pod will restart. Ensure the values stay within the defined limits; otherwise, the commit will fail.

Procedure

Enter configuration mode and set the desired BPF map sizes using the following commands:

Example:

config
            [no] cilium bpf auth-map-max <value>
            [no] cilium bpf fragments-map-max <value>
            [no] cilium bpf lb-affinity-map-max <value>
            [no] cilium bpf lb-maglev-map-max <value>
            [no] cilium bpf lb-maglev-table-size <value>
            [no] cilium bpf lb-map-max <value>
            [no] cilium bpf lb-rev-nat-map-max <value>
            [no] cilium bpf lb-service-backend-map-max <value>
            [no] cilium bpf lb-service-map-max <value>
            [no] cilium bpf lb-source-range-map-max <value>
            [no] cilium bpf map-dynamic-size-ratio <value>
            [no] cilium bpf neigh-global-max <value>
            [no] cilium bpf node-map-max <value>
            [no] cilium bpf policy-map-max <value>
            exit
  • You don't need to configure all map sizes; adjust them as needed for your setup.

  • By default, this CLI doesn't set any values, so Cilium BPF map sizes will follow Cilium's standards.

  • After committing changes in this CLI, the Cilium pod will restart.

  • Ensure the values stay within the defined limits. Else, the commit will fail.

Use the following table as a reference for the maximum size associated with these commands.

Command

Description

Range

cilium bpf auth-map-max

Maximum size for the BPF auth map

65536 to 4194304

cilium bpf fragments-map-max

Maximum size for the BPF fragments map

4096 to 65536

cilium bpf lb-affinity-map-max

Maximum size for the BPF load balancer affinity map

65536 to 4194304

cilium bpf lb-maglev-map-max

Maximum size for the BPF load balancer Maglev map

65536 to 4194304

cilium bpf lb-maglev-table-size

Size of the BPF load balancer Maglev lookup table.

MAGLEV_TABLE_SIZE_251

MAGLEV_TABLE_SIZE_509

MAGLEV_TABLE_SIZE_1021

MAGLEV_TABLE_SIZE_2039

MAGLEV_TABLE_SIZE_4093

MAGLEV_TABLE_SIZE_8191

MAGLEV_TABLE_SIZE_16381

MAGLEV_TABLE_SIZE_32749

MAGLEV_TABLE_SIZE_65521

MAGLEV_TABLE_SIZE_131071

cilium bpf lb-map-max

Maximum size for the BPF load balancer map

65536 to 4194304

cilium bpf lb-rev-nat-map-max

Maximum size for the BPF load balancer reverse NAT map.

65536 to 4194304

cilium bpf lb-service-backend-map-max

Maximum size for the BPF load balancer service backend map.

65536 to 4194304

cilium bpf lb-service-map-max

Maximum size for the BPF load balancer service map.

65536 to 4194304

cilium bpf lb-source-range-map-max

Maximum size for the BPF load balancer source range

65536 to 4194304

cilium bpf map-dynamic-size-ratio

Ratio used for dynamically sizing BPF maps relative to the amount of memory available

0.0 to 1.0

cilium bpf neigh-global-max

Global maximum size for the BPF neighbor map.

65536 to 4194304

cilium bpf node-map-max

Maximum size for the BPF node map

16384 to 4194304

cilium bpf policy-map-max

Maximum size for the BPF policy map.

8192 to 16384


Enable the Cilium Hubble Statistics

Procedure

Enter configuration mode and enable Hubble statistics for data collection:

Example:


            config
            metrics collection
            exit
          
Note

This CLI is disabled by default. Enabling the Hubble statistics will restart the Cilium pod.


Enable or disable ULB data path logging

Data path logging is a separate cluster-wide troubleshooting control. ULB data-path logging is disabled by default. Set spec.dataPathLogging.enable to true in ulb-logging to enable it and to false to disable it. This setting affects only eBPF data-path diagnostic logging; normal component logging remains available.

Procedure

1.

Configure the supported singleton UlbLogging resource named ulb-logging.

apiVersion: lbs.cisco.com/v1alpha1
kind: UlbLogging
metadata:
  name: ulb-logging
spec:
  dataPathLogging:
    enable: true
2.

Verify that the resource reports an Applied phase:

kubectl get ulbloggings ulb-logging
Note

Data path logging is intended only for brief, controlled troubleshooting. Enabling it can generate a high volume of diagnostic output and cause a significant spike in CPU utilization, particularly under high traffic. Do not leave data path logging enabled during normal production operation. Enable it only long enough to reproduce the issue and collect the required information, and then disable it immediately