Hi Santiago, On Tue, Sep 01, 2020 at 01:01:27PM +0200, Santiago R.R. wrote: > Source: linux > Version: 4.19.118-2 > Severity: important > Tags: ipv6 upstream fixed-upstream > > IPv6 connectivity (and other network protocols relying on multicast) are > broken when using a Dell D6000 USB-C dock. > Quoting Miguel Rodríguez that filed the equivalent bug in ubuntu: > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1779173: > > "Dell D6000 exposes a CDC_NCM device for Ethernet traffic. However, > multicast Ethernet traffic is not processed making IPv6 not functional. > Other services, like mDNS used for LAN service discovery are also > hindered. > > The actual reason is that CDC_NCM driver was not processing requests to > filter (admit) multicast traffic. I provide two patches to the linux > kernel that admit all Ethernet multicast traffic whenever a multicast > group is being joined. > > The solution is not optimal, as it makes the system receive more traffic > than that strictly needed, but otherwise this only happens when the > computer is connected to a dock and thus is running on AC power. I > believe it is not worth the hassle to join only the requested groups. > This is the same that is done in the CDN_ETHER driver." > > The patches proposed by Miguel Rodríguez have been merged upstream, and > are part of 5.9-rc1 now. C.f. commits: > 37a2ebdd9e597ae1a0270ac747883ea8f6f767b6 > e10dcb1b6ba714243ad5a35a11b91cc14103a9a9 > e506addeff844237d60545ef4f6141de21471caf > 0226009ce0f6089f9b31211f7a2703cf9a327a01
Thanks for the report, if I'm not mistaken this is the same as #965074. Can you request upstream backports of the needed fixes into the applicable stable releases (and as I understand you back to v4.19.y)? Regards, Salvatore
