Summary

When an Archer BE550 is used as a mesh satellite node (wireless backhaul), its DHCP client enters an abnormal renewal loop, sending DHCP RENEW requests every ~30–40 seconds despite receiving a long lease time (several days).

This behavior can overload or destabilize some DHCP servers and is not compliant with normal DHCP client behavior.

Observed Behavior

• The mesh node successfully receives a DHCP lease with a long duration (≈ 7 days).

• Immediately after receiving the ACK, the node logs:

  “1/2 lease passed, enter renewing state”

• The node then renews the lease repeatedly every ~30–40 seconds.

• This loop continues indefinitely.

Expected Behavior

• DHCP renewal should occur at T1 ≈ 50% of lease time, not immediately.

• With a multi-day lease, renewals should happen after several days, not seconds.

Key Evidence (from device logs)

Example pattern observed repeatedly:

receive ack from server with lease ≈ 600000 seconds 1/2 lease passed, enter renewing state send renew request

This indicates that the DHCP client miscalculates the lease timer.

Scope of the Issue

• Occurs only on the mesh satellite node

• The main BE550 (root node) does not show this behavior

• Occurs with:

  • Wireless mesh backhaul (Wi-Fi 6/6E/7)

  • Smart Connect enabled or disabled

  • MLO enabled or disabled

• The issue persists even with:

  • Fixed channels

  • Reduced channel width

  • Long DHCP lease times

Workarounds Tested

• Using a static IP on the main node stops the issue for that device.

• Mesh satellite nodes cannot keep a static IP (settings are overridden in mesh mode).

• DHCP reservation on the server side keeps the IP stable but does not stop the renew loop.

• Changing Wi-Fi performance settings may reduce frequency but does not fully fix the issue.

Impact

• Excessive DHCP traffic

• Potential DHCP service instability on some routers/firewalls

• Difficult to diagnose unless DHCP logs are inspected

• Affects advanced network setups more severely

Conclusion

This appears to be a firmware bug in the DHCP client implementation of the Archer BE550 mesh satellite node, where the lease timer is incorrectly evaluated, causing immediate renewal loops.

A firmware fix is recommended to correct DHCP lease timing logic in mesh mode.