Forum Help
cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Show  only  | Search instead for 
Did you mean: 
evertonian88
Beginner

‎23-06-2026 18h42 - edited ‎23-06-2026 18h44

71 Views
Message 1 of 1

Intermittent PPP Session Failures & Packet Corruption (ERR_SSL_BAD_RECORD_MAC_ALERT)

Hi everyone,

I’m hoping a BT Community Mod or network specialist can kindly help escalate a stubborn connection issue. For the past few months, I've been getting persistent ERR_SSL_BAD_RECORD_MAC_ALERT errors across secure HTTPS websites on all devices (both wired desktop and Wi-Fi mobile). The issue completely vanishes when browsing on mobile data, isolating it to my BT broadband connection.

I have run extensive local network diagnostics via Command Prompt and the BT Connection Tester, which points directly to an authentication/gateway routing issue on the BT network side.

  1. Diagnostic Pings and MTU Restriction:

  • Running standard unfragmented pings to Google with sizes 1472 and 1464 completely fails with the message: "Packet needs to be fragmented but DF set."

  • Manual testing reveals the absolute maximum unfragmented payload size the line will currently pass is 1460 bytes (locking the line's maximum working MTU at 1488).

  • I have manually updated my network interface configurations down to 1488 to compensate, flushed DNS, and tested custom public DNS to bypass potential server-side mangling, but secure packets are still getting dropped or corrupted mid-transit.

  1. BT Connection Tester Official Results: I ran the automated BT wholesale tester, and it explicitly flagged a network-side fault with the following output: "Test results: You might have some connection stability issues. This can result in your connection dropping out. Technical details: Your hub could be in sync with the exchange or cabinet, but not connecting to the gateway. If there's no PPP session it's likely to be a problem with our network."

I figure because the physical line syncs fine but the underlying PPP session is failing to authenticate cleanly with the gateway, my secure web traffic is having its cryptographic handshakes broken, triggering the SSL MAC errors?

Could a moderator please look into this, check my error/interleaving rates on the line, and order a port reset or clear any hung/stale PPP sessions at the gateway exchange end? 

Or any suggestions at all on how to resolve would be hugely appreciated - I've spent months trying to resolve to no joy.

Thank you in advance!

0 Ratings
Reply