Package: linux-image-4.0.0-2-amd64 Severity: important Dear Maintainer,
I have run into a bug while using Intel X710 NICs with the i40e driver. This bug does *not* affect 3.16, but does affect the 4.0 kernel in sid. The bug means that when in promiscuous mode, packets sent out the NIC are also reflected back in. When adding a port to a bridge, the port is put into promisc mode, and the reflected packets wreak havoc with the FDB. The problem is easily detectable when running a packet capture: any packets sent out appear to be duplicated in the capture. When a VM is part of a bridge its outgoing packets are forwarded out but also reflected back in. This updates the bridge's FDB which now thinks the VM's MAC is on the uplink port. The response then arrives but is dropped because it arrives on the same port the bridge thinks it should forward it out on (and hairpinning is disabled, and wouldn't help here anyway). When running lldpd, the local machine also appears as a remote machine in its database. The issue is discussed in https://communities.intel.com/message/305975 A patch working around the issue has gone into 4.1 as commit fc60861e9b00388fd11d7995a60bf0b1e61dba93. https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=fc60861e9b00388fd11d7995a60bf0b1e61dba93 Hope this helps! Best regards, Chris -- System Information: Debian Release: 8.1 APT prefers stable-updates APT policy: (500, 'stable-updates'), (500, 'stable') Architecture: amd64 (x86_64) Kernel: Linux 4.0.0-2.tcl.1-amd64 (SMP w/24 CPU cores) Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: https://lists.debian.org/[email protected]
