Display cluster connections in ONTAP
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You can display all the active connections in the cluster or a count of active connections on the node by client, logical interface, protocol, or service. You can also display all the listening connections in the cluster.
Display active connections by client (cluster administrators only)
You can view the active connections by client to verify the node that a specific client is using and to view possible imbalances between client counts per node.
The count of active connections by client is useful in the following scenarios:
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Finding a busy or overloaded node.
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Determining why a particular client's access to a volume is slow.
You can view details about the node that the client is accessing and then compare it with the node on which the volume resides. If accessing the volume requires traversing the cluster network, clients might experience decreased performance because of the remote access to the volume on an oversubscribed remote node.
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Verifying that all nodes are being used equally for data access.
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Finding clients that have an unexpectedly high number of connections.
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Verifying whether certain clients have connections to a node.
Display a count of the active connections by client on a node by using the network connections active show-clients command.
Learn more about the network connections active show-clients command in the ONTAP command reference.
network connections active show-clients
Node Vserver Name Client IP Address Count
------ -------------- ----------------- ------
node0 vs0 192.0.2.253 1
vs0 192.0.2.252 2
Cluster 192.10.2.124 5
node1 vs0 192.0.2.250 1
vs0 192.0.2.252 3
Cluster 192.10.2.123 4
node2 vs1 customer.example.com 1
vs1 192.0.2.245 3
Cluster 192.10.2.122 4
node3 vs1 customer.example.org 1
vs1 customer.example.net 3
Cluster 192.10.2.121 4
Display active connections by protocol (cluster administrators only)
You can display a count of the active connections by protocol (TCP or UDP) on a node to compare the usage of protocols within the cluster.
The count of active connections by protocol is useful in the following scenarios:
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Finding the UDP clients that are losing their connection.
If a node is near its connection limit, UDP clients are the first to be dropped.
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Verifying that no other protocols are being used.
Display a count of the active connections by protocol on a node by using the network connections active show-protocols command.
For more information about this command, see the man page.
network connections active show-protocols
Node Vserver Name Protocol Count
------- ------------ --------- ------
node0
vs0 UDP 19
Cluster TCP 11
node1
vs0 UDP 17
Cluster TCP 8
node2
vs1 UDP 14
Cluster TCP 10
node3
vs1 UDP 18
Cluster TCP 4
Display active connections by service (cluster administrators only)
You can display a count of the active connections by service type (for example, by NFS, SMB, mount, and so on) for each node in a cluster. This is useful to compare the usage of services within the cluster, which helps to determine the primary workload of a node.
The count of active connections by service is useful in the following scenarios:
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Verifying that all nodes are being used for the appropriate services and that the load balancing for that service is working.
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Verifying that no other services are being used. Display a count of the active connections by service on a node by using the
network connections active show-servicescommand.
For more information about this command, see the man page: ONTAP command reference
network connections active show-services
Node Vserver Name Service Count
--------- -------------- --------- ------
node0
vs0 mount 3
vs0 nfs 14
vs0 nlm_v4 4
vs0 cifs_srv 3
vs0 port_map 18
vs0 rclopcp 27
Cluster ctlopcp 60
node1
vs0 cifs_srv 3
vs0 rclopcp 16
Cluster ctlopcp 60
node2
vs1 rclopcp 13
Cluster ctlopcp 60
node3
vs1 cifs_srv 1
vs1 rclopcp 17
Cluster ctlopcp 60
Display active connections by LIF on a node and SVM
You can display a count of active connections for each LIF, by node and storage virtual machine (SVM), to view connection imbalances between LIFs within the cluster.
The count of active connections by LIF is useful in the following scenarios:
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Finding an overloaded LIF by comparing the number of connections on each LIF.
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Verifying that DNS load balancing is working for all data LIFs.
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Comparing the number of connections to the various SVMs to find the SVMs that are used the most.
Display a count of active connections for each LIF by SVM and node by using the network connections active show-lifs command.
For more information about this command, see the man page: ONTAP command reference
network connections active show-lifs
Node Vserver Name Interface Name Count
-------- ------------ --------------- ------
node0
vs0 datalif1 3
Cluster node0_clus_1 6
Cluster node0_clus_2 5
node1
vs0 datalif2 3
Cluster node1_clus_1 3
Cluster node1_clus_2 5
node2
vs1 datalif2 1
Cluster node2_clus_1 5
Cluster node2_clus_2 3
node3
vs1 datalif1 1
Cluster node3_clus_1 2
Cluster node3_clus_2 2
Display active connections in a cluster
You can display information about the active connections in a cluster to view the LIF, port, remote host, service, storage virtual machines (SVMs), and protocol used by individual connections.
Viewing the active connections in a cluster is useful in the following scenarios:
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Verifying that individual clients are using the correct protocol and service on the correct node.
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If a client is having trouble accessing data using a certain combination of node, protocol, and service, you can use this command to find a similar client for configuration or packet trace comparison.
Display the active connections in a cluster by using the network connections active show command.
For more information about this command, see the man page: ONTAP command reference.
The following command shows the active connections on the node node1:
network connections active show -node node1 Vserver Interface Remote Name Name:Local Port Host:Port Protocol/Service ------- ------------------ ------------------ ---------------- Node: node1 Cluster node1_clus_1:50297 192.0.2.253:7700 TCP/ctlopcp Cluster node1_clus_1:13387 192.0.2.253:7700 TCP/ctlopcp Cluster node1_clus_1:8340 192.0.2.252:7700 TCP/ctlopcp Cluster node1_clus_1:42766 192.0.2.252:7700 TCP/ctlopcp Cluster node1_clus_1:36119 192.0.2.250:7700 TCP/ctlopcp vs1 data1:111 host1.aa.com:10741 UDP/port-map vs3 data2:111 host1.aa.com:10741 UDP/port-map vs1 data1:111 host1.aa.com:12017 UDP/port-map vs3 data2:111 host1.aa.com:12017 UDP/port-map
The following command shows the active connections on SVM vs1:
network connections active show -vserver vs1 Vserver Interface Remote Name Name:Local Port Host:Port Protocol/Service ------- ------------------ ------------------ ---------------- Node: node1 vs1 data1:111 host1.aa.com:10741 UDP/port-map vs1 data1:111 host1.aa.com:12017 UDP/port-map
Display listening connections in a cluster
You can display information about the listening connections in a cluster to view the LIFs and ports that are accepting connections for a given protocol and service.
Viewing the listening connections in a cluster is useful in the following scenarios:
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Verifying that the desired protocol or service is listening on a LIF if client connections to that LIF fail consistently.
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Verifying that a UDP/rclopcp listener is opened at each cluster LIF if remote data access to a volume on one node through a LIF on another node fails.
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Verifying that a UDP/rclopcp listener is opened at each cluster LIF if SnapMirror transfers between two nodes in the same cluster fail.
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Verifying that a TCP/ctlopcp listener is opened at each intercluster LIF if SnapMirror transfers between two nodes in different clusters fail.
Display the listening connections per node by using the network connections listening show command.
network connections listening show Vserver Name Interface Name:Local Port Protocol/Service ---------------- ------------------------------- ---------------- Node: node0 Cluster node0_clus_1:7700 TCP/ctlopcp vs1 data1:4049 UDP/unknown vs1 data1:111 TCP/port-map vs1 data1:111 UDP/port-map vs1 data1:4046 TCP/sm vs1 data1:4046 UDP/sm vs1 data1:4045 TCP/nlm-v4 vs1 data1:4045 UDP/nlm-v4 vs1 data1:2049 TCP/nfs vs1 data1:2049 UDP/nfs vs1 data1:635 TCP/mount vs1 data1:635 UDP/mount Cluster node0_clus_2:7700 TCP/ctlopcp