Dear TM Unifi Support Team,
I am experiencing frequent disconnections on my Unifi broadband connection and would like your assistance in troubleshooting the issue. Based on my MikroTik router logs, I am seeing repeated occurrences of LCP TermReq, LCP ProtRej (0x82, 0x81), and missing LCP Echo Replies, which indicate instability in the PPPoE session.
Summary of the Issue:
- My PPPoE connection drops intermittently, and logs show
LCP TermReq, suggesting forced disconnections by the ISP. - My router receives
LCP ProtRej 0x82, 0x81, indicating protocol rejections from the ISP’s side. - The MTU is auto-negotiating below 1492, possibly due to VRRP, VXLAN, or Huawei vBRAS infrastructure, affecting compatibility with high-security services.
Observations from Other Unifi Customers:
I have noticed that Unifi customers under Juniper Networks-based BRAS have a much more stable connection and support RFC4638 (PPPoE MTU 1500):
imse01.tsk_tp-re0(CC:E1:7F:AB:8F:CF) – Stable connection, supports RFC4638.imse01.kmr_sja-re0(CC:E1:7F:AB:F7:CF) – Stable connection, supports RFC4638.
Additionally, in 2021, my area was served by imse01.mc_rsh-re0 (F0:1C:2D:22:87:C3)`, which provided a very stable connection. However, after switching to the current infrastructure, my connection has become unreliable.
Connection Details:
- PPPoE Username: @unifi
- Service Type: Unifi Ultra (2Gbps)
- Router Model: MikroTik RB5009UG+S+IN
Troubleshooting Steps I Have Taken:
✔ Checked and replaced cables between my router and ONU.
✔ Adjusted MTU settings (tested 1492, 1488, 1480, 1460).
✔ Updated RouterOS firmware to the latest version.
✔ Disabled unnecessary protocols (PAP/CHAP only).
Request for RFC4638 Support (PPPoE MTU 1500):
I would like TM Unifi to enable RFC4638, which allows PPPoE to use MTU 1500 bytes.
This is important because some high-security servers block clients with lower MTU values to prevent VPN circumvention, and Juniper-based BRAS users already benefit from this feature.
Request for Investigation:
I would appreciate it if your team could:
- Investigate whether ISP-side configurations (BRAS policies, MTU restrictions, or disconnection timeouts) are causing my issues.
- Confirm if RFC4638 can be enabled for my connection to improve stability and compatibility.
Please let me know if you need additional diagnostics from my side. I look forward to your response and assistance in resolving this issue.
Best regards,
<Name>
📞 Contact:
🔢 Account Number: