Bug Report: ER605 v2 - SNMP Incoherency and Data Merging during WAN Failover

Bug Report: ER605 v2 - SNMP Incoherency and Data Merging during WAN Failover

Bug Report: ER605 v2 - SNMP Incoherency and Data Merging during WAN Failover
Bug Report: ER605 v2 - SNMP Incoherency and Data Merging during WAN Failover
2 weeks ago
Model: ER605 (TL-R605)  
Hardware Version: V2
Firmware Version: 2.2.5 Build 20240522 Rel.75860

There is a critical discrepancy in how the SNMP agent reports interface statistics (IF-MIB) when the router enters Link Backup (Failover) mode. Currently, the router fails to maintain independent traffic accounting for physical ports during an emergency switch-over.

Observed Anomalous Behavior:

  1. Traffic Misassignment: When the Primary WAN (Port 1) goes offline, the router correctly routes traffic through the Backup WAN1 (Port 2). However, the SNMP agent begins reporting the Backup WAN1's traffic under the Primary WAN's index (1026) instead of its own physical index (1038).

  2. Loss of Granularity: Data counters for the Backup Port (1038) remain static or show negligible values, while the Primary Port index (which is physically disconnected/offline) acts as a "logical aggregator" for all global outbound traffic.

  3. Severe Update Latency: During failover, the SNMP ifInOctets and ifOutOctets counters update with extreme delay (often exceeding 120 seconds) and fail to reflect the actual throughput (e.g., a 180MB download is reported as <1MB).

Required Fix / Feature Request: It is essential that a future firmware update ensures strict physical port isolation for SNMP counters. Specifically:

  • Independence: Traffic data must be exposed separately for each physical port at all times. The SNMP agent must not "merge" or "redirect" traffic statistics of the Backup WAN into the Primary WAN’s OID/Index during failover.

  • Real-time Accuracy: IF-MIB counters must reflect the real-time bitstream of the physical silicon port, regardless of the logical routing state (Failover/Load Balance).

  • Consistency: If 100MB passes through the physical pins of Port 2, those 100MB must appear under Index 1038, even if Port 1 is designated as the "Default Gateway."

Impact: The current behavior makes professional network monitoring (via Zabbix, PRTG, or custom scripts) impossible. Network administrators cannot accurately track data usage on backup lines (which often have data caps) because the router "hides" this traffic within the offline primary interface's counters.

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#1
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Re:Bug Report: ER605 v2 - SNMP Incoherency and Data Merging during WAN Failover
2 weeks ago

As shown in the screenshot, Port 1(WAN) is Offline and Port 2 (WAN1) is Online, yet SNMP continues to report traffic on Port 1's index while Port 2 remains at zero. This proves the MIB database mapping is broken during Failover.

 


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Re:Bug Report: ER605 v2 - SNMP Incoherency and Data Merging during WAN Failover
a week ago
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Re:Bug Report: ER605 v2 - SNMP Incoherency and Data Merging during WAN Failover
a week ago - last edited a week ago

Hi  @DraftmanCorp 

 

Thanks for posting here.

The firmware for the ER605 is not the latest. Please first update it to the latest and see if the situation persists:

https://support.omadanetworks.com/en/product/er605/v2/?resourceType=download

 

 

When did you first notice this situation? Did it work correctly before?

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Re:Bug Report: ER605 v2 - SNMP Incoherency and Data Merging during WAN Failover
a week ago

  @Vincent-TP 

I noticed the issue specifically during a Fiber outage while the router was in Link Backup (Failover) mode.

Previously, when both WANs were 'Online', the SNMP readings were correct and independent (Fiber on index 1026, 4G on index 1038).

The anomaly starts only when the Primary WAN goes 'Offline'. At that exact moment, the SNMP agent stops updating the Backup WAN index (1038) and starts merging all the backup traffic into the Primary WAN index (1026). This is clearly a logical mapping error in the SNMP daemon during the transition to Failover state.

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Re:Bug Report: ER605 v2 - SNMP Incoherency and Data Merging during WAN Failover
Thursday - last edited Friday

Hi  @DraftmanCorp 

 

Thanks for the reply.

 

To confirm, you have updated the firmware to the latest one and the situation persists, right?

 

Apart from ifInOctets and ifOutOctets counters, did you check other counters? if yes, please also give us the OID. Thanks.

 

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