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Author Topic: IPv6 problem with Huawei HG612 VDSL modem with OEM firmware  (Read 322 times)


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IPv6 problem with Huawei HG612 VDSL modem with OEM firmware
« on: September 04, 2020, 04:04:45 PM »

I have an Huawei HG612 VDSL modem, with the original OEM firmware restored instead of the BT Openreach crippled firmware, as described here on Kitz.

I have dual stack internet, not tunnelled, with Zen as my ISP. I get about 37megabits/sec down, 5.5megabits/sec up, so it's very easy to saturate my uplink.

I use a dedicated linux system as my firewall/router, which means I can monitor traffic with tcpdump and run all the standard tools.

I discovered recently the HG612 seems to have a problem with prioritising IPv6 traffic over IPv4.

If I flood my uplink to my ISP with IPv6 traffic, e.g. uploading a video to youtube, then the modem appears to drop all IPv4 packets. I can see the pings going out to the modem in the pppoe packets, but nothing comes back! The moment the ipv6 ceases, ipv4 works again!

Is there anyone running dual stack with a separate router and HG612 modem who can try and repeat this problem?

My only solution was to switch to my spare, an ECI bfocus VDSL modem, and it totally solved the problem.