High neighbor discovery (ND) cache usage for Cisco Nexus

Vendor

Cisco

Description

Indeni will alert when the number of neighbor discovery entries stored by a device is nearing the allowed limit.

Remediation Steps

Identify the cause of the large neighbor discovery table. If it is due to a legitimate cause, such as a high number of hosts visible on the available networks, please contact your technical support provider.

How does this work?

This script logs into the Cisco Nexus switch using SSH and retrieves the output of the "show inventory" command. The reported device type is used to identify the maximum size of the neighbor discovery cache based on a static table. Nexus 3000: 1,500 (http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus3000/sw/scalability/7x/b_Nexus3k_Verified_Scalability_7x/b_Nexus3k_Verified_Scalability_7x_chapter_01.html) Nexus 5000: 4,000 (http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/configuration_limits/limits_513/nexus_5000_config_limits_513.html) Nexus 5500: 4,000 (http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5500/sw/Verified_Scalability/700N11/b_N5500_Verified_Scalability_700N11/b_N5500_Verified_Scalability_700N11_chapter_01.html Nexus 5600: 16,000 (http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5600/sw/verified_scalability/701N11/b_N5600_Verified_Scalability_701N11/b_N6000_Verified_Scalability_700N11_chapter_01.html) Nexus 6000: 16,000 (http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5600/sw/verified_scalability/701N11/b_N5600_Verified_Scalability_701N11/b_N6000_Verified_Scalability_700N11_chapter_01.html) Nexus 7000: 30,000 (http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/6_x/nx-os/unicast/configuration/guide/b-7k-Cisco-Nexus-7000-Series-NX-OS-Unicast-Routing-Configuration-Guide-Release-6x/n7k_unicast_managinging_rib_fib.html) Nexus 9300: 5,000 (http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/7-x/scalability/guide_703I11/b_Cisco_Nexus_9000_Series_NX-OS_Verified_Scalability_Guide_703I11.html) Nexus 9500: 30,000 (http://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/7-x/scalability/guide_703I11/b_Cisco_Nexus_9000_Series_NX-OS_Verified_Scalability_Guide_703I11.html)

Why is this important?

Identify the maximum number of IPv6 neighbor entries a certain Nexus platform can support. This information is used to generate reports if the total number of entries reaches the limit.

Without Indeni how would you find this?

This data is not available through SNMP or syslog.

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