Incomplete ARP Table Retrieval via SNMP OID on ICX Switch
Summary
On firmware version 10.0.10g_cdx, the ARP table retrieved through SNMP OID polling appears to be incomplete, with certain ARP entries not being returned in the SNMP response.Question
- Why are some ARP entries not being returned through SNMP?
- What issue is observed when retrieving the ARP table via SNMP on ICX switches?
Customer Environment
The customer is deploying ICX 8200 switches running version 10010g_cd5 and would like to retrieve the ARP table via SNMP. However, they are observing that only a few ARP entries are appearing on the SNMP server.Symptoms
They are performing an SNMP walk using the following OIDs to obtain the ARP table entries:
- The ARP table retrieved through SNMP polling does not contain all ARP entries present on the ICX switch.
- A discrepancy is observed between the output of the CLI command (e.g.,
show arp) and the ARP entries returned via the SNMP OID. - Network management or monitoring tools relying on SNMP display only a partial ARP table.
- Some dynamic ARP entries are missing from the SNMP response, even though they are visible in the switch's ARP table.
- The issue is consistently observed on switches running version 10.0.10g_cdx when polling the affected SNMP OID.
Root Cause
The issue was identified as a defect in the software code on version 10.0.10g_cdx, which causes the SNMP process to return an incomplete ARP table when queried using the relevant SNMP OID. As a result, certain ARP entries present in the switch ARP table are not included in the SNMP response, leading to discrepancies between the CLI output and the data retrieved by the SNMP polling tool.Troubleshooting Steps
Below outputs are seen in lab:
ICX8200-24ZP Router#sh ver
Copyright (c) Ruckus Networks, Inc. All rights reserved.
UNIT 1: compiled on Nov 8 2025 at 09:23:50 labeled as RDR10010g_cd5
(105604380 bytes) from Secondary RDR10010g_cd5.bin (UFI)
SW: Version 10.0.10g_cd5T253
Compressed Secondary Boot Code size = 2097664, Version:10.2.12T255 (rdu10212)
Compiled on Wed Jul 9 10:04:08 2025
ICX8200-24ZP Router#sh arp
Total number of ARP entries: 7
Entries in default routing instance:
No. IP Address MAC Address Type Age Port Status
1 10.177.85.1 02e0.5253.d6e6 Dynamic 1 1/1/1 Valid
2 10.177.85.2 609c.9f20.5400 Dynamic 1 1/1/1 Valid
3 10.177.85.3 cc4e.2438.a600 Dynamic 1 1/1/1 Valid
4 192.168.30.2 0050.56b6.388d Dynamic 1 1/1/24 Valid
5 192.168.30.3 cc4e.248a.15f0 Dynamic 2 1/1/2 Valid
6 192.168.40.2 cc4e.248a.15f0 Dynamic 1 1/1/2 Valid
7 192.168.50.2 cc4e.248a.15f0 Dynamic 0 1/1/2 Valid
ICX8200-24ZP Router#sh ip int
Interface IP-Address OK? Method Status Protocol VRF
Ve 1 10.177.85.23 YES manual up up default-vrf
Ve 30 192.168.30.1 YES NVRAM up up default-vrf
Ve 40 192.168.40.1 YES NVRAM up up default-vrf
Ve 50 192.168.50.1 YES NVRAM up up default-vrf
Using ireasoning Mib browser, below outputs are seen:
Observation:
Values such as 16777217 seem to be the VLAN ID values returned by SNMP.
We noticed:
-
VLANs mapped to odd IDs (16777217, 16777219) have ARP tables.
-
VLANs mapped to even IDs (16777218, 16777220) do not have ARP tables.
Resolution
The fix has been implemented on 10.0.10g_cd7.Article Number:
000015402
Updated:
July 30, 2026 12:51 PM (about 1 month ago)
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