Date: Wed, 18 Dec 2024 14:22:12 +0000 From: bugzilla-noreply@freebsd.org To: doc@FreeBSD.org Subject: [Bug 283400] if_bridge(4) contains false statement about link address selection Message-ID: <bug-283400-9@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D283400 Bug ID: 283400 Summary: if_bridge(4) contains false statement about link address selection Product: Documentation Version: Latest Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: Manual Pages Assignee: bugs@FreeBSD.org Reporter: jason.mann@gmail.com CC: doc@FreeBSD.org if_bridge(4) contains the following paragraph: The if_bridge interface randomly chooses a link (MAC) address in the range reserved for locally administered addresses when it is created. This address is guaranteed to be unique only across all if_bridge interfaces on the local machine. Thus you can theoretically have two bridges on different machines with the same link addresses. The addre= ss can be changed by assigning the desired link address using ifconfig(8). It appears that the choice of bridge link address is not random, but is ins= tead based on the value of kern.hostid. If two systems mistakenly end up with the same hostid, when using disk clon= ing for example, then the MAC address chosen for bridge interfaces will also be= the same. To avoid confusion, this should be clarified. Also, the MAC address chosen for a bridge appears to always begin with the octets 58:9c:fc:10:xx:xx. The '8' as the second digit of the first octet indicates a universally administered address, not a locally administered on= e. https://en.wikipedia.org/wiki/MAC_address#Ranges_of_group_and_locally_admin= istered_addresses --=20 You are receiving this mail because: You are on the CC list for the bug.=
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