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Configuring switchd

The switchd service enables the switch to communicate with Cumulus Linux and all the applications running on Cumulus Linux.

Configure switchd Parameters

You can control certain options associated with the switchd process. For example, you can set polling intervals, optimize ACL hardware resources for better utilization, configure log message levels, set the internal VLAN range, and configure VXLAN encapsulation and decapsulation.

To configure the switchd parameters, edit the /etc/cumulus/switchd.conf file. Change the setting and uncomment the line if needed. The switchd.conf file contains comments with a description for each setting.

The following example shows the first few lines of the /etc/cumulus/switchd.conf file.

cumulus@switch:~$ sudo nano /etc/cumulus/switchd.conf
#
# /etc/cumulus/switchd.conf - switchd configuration file
#

# Statistic poll interval (in msec)
#stats.poll_interval = 2000

# Buffer utilization poll interval (in msec), 0 means disable
#buf_util.poll_interval = 0

# Buffer utilization measurement interval (in mins)
#buf_util.measure_interval = 0

# Optimize ACL HW resources for better utilization
#acl.optimize_hw = FALSE

# Enable Flow based mirroring.
#acl.flow_based_mirroring = TRUE

# Enable non atomic acl update
acl.non_atomic_update_mode = FALSE

# Send ARPs for next hops
#arp.next_hops = TRUE

# Kernel routing table ID, range 1 - 2^31, default 254
#route.table = 254
...

The following table describes the /etc/cumulus/switchd.conf file parameters and indicates if you need to restart switchd with the sudo systemctl restart switchd.service command or reload switchd with the sudo systemctl reload switchd.service command for changes to take effect when you update the setting.

Restarting the switchd service causes all network ports to reset in addition to resetting the switch hardware configuration.

Parameter Description switchd reload or restart
stats.poll_interval The statistics polling interval in milliseconds.
The default setting is 2000.
restart
buf_util.poll_interval The buffer utilization polling interval in milliseconds. 0 disables buffer utilization polling.
The default setting is 0.
restart
buf_util.measure_interval The buffer utilization measurement interval in minutes.
The default setting is 0.
restart
acl.optimize_hw Optimizes ACL hardware resources for better utilization.
The default setting is FALSE.
restart
acl.flow_based_mirroring Enables flow-based mirroring.
The default setting is TRUE.
restart
acl.non_atomic_update_mode Enables non atomic ACL updates
The default setting is FALSE.
reload
arp.next_hops Sends ARPs for next hops.
The default setting is TRUE.
restart
route.table The kernel routing table ID. The range is between 1 and 2^31.
The default is 254.
restart
route.host_max_percent The maximum neighbor table occupancy in hardware (a percentage of the hardware table size).
The default setting is 100.
restart
coalescing.reducer The coalescing reduction factor for accumulating changes to reduce CPU load.
The default setting is 1.
restart
coalescing.timeout The coalescing time limit in seconds.
The default setting is 10.
restart
ignore_non_swps Ignore routes that point to non-swp interfaces.
The default setting is TRUE.
restart
disable_internal_parity_restart Disables restart after a parity error.
The default setting is TRUE.
restart
disable_internal_hw_err_restart Disables restart after an unrecoverable hardware error.
The default setting is FALSE.
restart
nat.static_enable Enables static NAT.
The default setting is TRUE.
restart
nat.dynamic_enable Enables dynamic NAT.
The default setting is TRUE.
restart
nat.age_poll_interval The NAT age polling interval in minutes. The minimum is 1 minute and the maximum is 24 hours. You can configure this setting only when nat.dynamic_enable is set to TRUE.
The default setting is 5.
restart
nat.table_size The NAT table size limit in number of entries. You can configure this setting only when nat.dynamic_enable is set to TRUE.
The default setting is 1024.
restart
nat.config_table_size The NAT configuration table size limit in number of entries. You can configure this setting only when nat.dynamic_enable is set to TRUE.
The default setting is 64.
restart
logging Configures logging in the format BACKEND=LEVEL. Separate multiple BACKEND=LEVEL pairs with a space. The BACKEND value can be stderr, file:filename, syslog, program:executable. The LEVEL value can be CRIT, ERR, WARN, INFO, DEBUG.
The default value is syslog=INFO
restart
interface.swp1.storm_control.broadcast Enables broadcast storm control and sets the number of packets per second (pps).
The default setting is 400.
reload
interface.swp1.storm_control.multicast Enables multicast storm control and sets the number of packets per second (pps).
The default setting is 3000.
reload
interface.swp1.storm_control.unknown_unicast Enables unicast storm control and sets the number of packets per second (pps).
The default setting is 2000.
reload
stats.vlan.aggregate Enables hardware statistics for VLANs and specifies the type of statistics needed. You can specify NONE, BRIEF, or DETAIL.
The default setting is BRIEF.
restart
stats.vxlan.aggregate Enables hardware statistics for VXLANs and specifies the type of statistics needed. You can specify NONE, BRIEF, or DETAIL.
The default setting is DETAIL.
restart
stats.vxlan.member Enables hardware statistics for VXLAN members and specifies the type of statistics needed. You can specify NONE, BRIEF, or DETAIL.
The default setting is BRIEF.
restart
stats.vlan.show_internal_vlans Show internal VLANs.
The default setting is FALSE.
restart
stats.vdev_hw_poll_interval The polling interval in seconds for virtual device hardware statisitcs.
The default setting is 5.
restart
resv_vlan_range The internal VLAN range.
The default setting is 3725-3999.
restart
netlink.buf_size The netlink socket buffer size in MB.
The default setting is 136314880.
restart
route.delete_dead_routes Delete routes on interfaces when the carrier is down.
The default setting is TRUE.
restart
vxlan.default_ttl The default TTL to use in VXLAN headers.
The default setting is 64.
restart
bridge.broadcast_frame_to_cpu Enables bridge broadcast frames to the CPU even if the SVI is not enabled.
The default setting is FALSE.
restart
bridge.unreg_mcast_init Initialize the prune module for IGMP snooping unregistered layer 2 multicast flood control.
The default setting is FALSE.
restart
bridge.unreg_v4_mcast_prune Enables unregistered layer 2 multicast prune to mrouter ports (IPv4).
The default setting is FALSE (flood unregistered layer 2 multicast traffic).
restart
bridge.unreg_v6_mcast_prune Enables unregistered layer 2 multicast prune to mrouter ports (IPv6).
The default setting is FALSE (flood unregistered layer 2 multicast traffic).
restart
netlink libnl logger The default setting is [0-5]. restart
netlink.nl_logger The default setting is 0. restart
vxlan.def_encap_dscp_action Sets the default VXLAN router DSCP action during encapsulation. You can specify copy if the inner packet is IP, set to set a specific value, or derive to derive the value from the switch priority.
The default setting is derive.
restart
vxlan.def_encap_dscp_value Sets the default VXLAN encapsulation DSCP value if the action is set.
restart
vxlan.def_decap_dscp_action Sets the default VXLAN router DSCP action during decapsulation. You can specify copy if the inner packet is IP, preserve to preserve the inner DSCP value, or derive to derive the value from the switch priority.
The default setting is derive.
restart
ipmulticast.unknown_ipmc_to_cpu Enables sending unknown IPMC to the CPU.
The default setting is FALSE.
restart
ptp.timestamping Enables PTP time stamping.
The default setting is TRUE.
restart
vrf_route_leak_enable_dynamic Enables dynamic VRF route leaking.
The default setting is FALSE.
restart
sync_queue_depth_val The event queue depth.
The default setting is 50000.
restart
route.route_preferred_over_neigh Sets the preference between a route and neighbor with the same IP address and mask. You can specify TRUE to prefer the route over the neighbor, FALSE to prefer the neighbor over the route, or BOTH to install both the route and neighbor.
The default setting is TRUE.
restart
evpn.multihoming.enable Enables EVPN multihoming.
The default setting is TRUE.
restart
evpn.multihoming.shared_l2_groups Enables sharing for layer 2 next hop groups.
The default setting is FALSE.
restart
evpn.multihoming.shared_l3_groups Enables sharing for layer 3 next hop groups.
The default setting is FALSE.
restart
evpn.multihoming.fast_local_protect Enables fast reroute for egress link protection. The default setting is FALSE. restart
link_flap_window The duration in seconds during which a link must flap the number of times set in the link_flap_threshold before Cumulus Linux sets the link to protodown and specifies linkflap as the reason.
The default setting is 10. A value of 0 disables link flap protection.
restart
link_flap_threshold The number of times the link must flap within the link flap window before Cumulus Linux sets the link to protodown and specifies linkflap as the reason.
The default setting is 5. A value of 0 disables link flap protection.
restart
res_usage_warn_threshold Sets the percentage over which forwarding resources (routes, hosts, MAC addresses) must go before Cumulus Linux generates a warning. You can set a value between 50 and 95.
The default setting is 90.
restart
res_warn_msg_int The time interval in seconds between resource warning messages. Warning messages generate only one time in the specified interval per resource type even if the threshold falls below or goes over the value set in res_usage_warn_threshold multiple times during this interval. You can set a value between 60 and 3600.
The default setting is 300.
restart

In addition to restarting switchd when you change certain /etc/cumulus/switchd.conf file parameters, you also need to restart switchd whenever you modify a switchd hardware configuration file (any *.conf file that requires making a change to the switching hardware, such as /etc/cumulus/datapath/traffic.conf). You do not have to restart the switchd service when you update a network interface configuration (for example, when you edit the /etc/network/interfaces file).