Date: Mon, 28 Aug 2006 15:44:28 +0200 From: Radim Kolar <hsn@netmag.cz> To: FreeBSD-gnats-submit@FreeBSD.org Cc: hsn@netmag.cz Subject: kern/102607: [if_bridge] don't generate random L2 address Message-ID: <E1GHhPg-00056N-Vm@sanatana.dharma> Resent-Message-ID: <200608281350.k7SDoJl4016888@freefall.freebsd.org>
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>Number: 102607 >Category: kern >Synopsis: [if_bridge] don't generate random L2 address >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: change-request >Submitter-Id: current-users >Arrival-Date: Mon Aug 28 13:50:19 GMT 2006 >Closed-Date: >Last-Modified: >Originator: Radim Kolar >Release: FreeBSD 6.1-STABLE i386 >Organization: sd >Environment: System: FreeBSD sanatana.dharma 6.1-STABLE FreeBSD 6.1-STABLE #3: Fri Aug 25 12:13:08 CEST 2006 root@sanatana.dharma:/usr/obj/usr/src/sys/UP i386 >Description: if_bridge interfaces have every boottime different L2 address. This behaviour is very different from other interfaces like network cards, they have L2 address in EPROMS. Because bridge interface is designed to look and work like other NIC cards, it should have static L2 address by default to make work of network admins easier, other BSDs complains about inet address moved and you can't use static IP in dhcpd. Because not every number can be used as L2 address for bridge, admin can make hard-to-find mistake when configuring static address by hand. >How-To-Repeat: >Fix: 1. change kernel code or to generate static IP address for bridge interface from attached member interfaces. or 2. use startup scripts to generate random number and store it somewhere in /var. or 3. Make system complain/warning if you set bridge0 to broadcast address. or 4. Document in if_bridge(4) that L2 address is random and document correct format of ethernet addresses. Problem with 1. is that address will change if you add or swap NICs in bridge, but it is still less likely to change than using random numbers now. >Release-Note: >Audit-Trail: >Unformatted:
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