Re: [2.4 PATCH] bugfix: ARP respond on all devices
From: Bill Davidsen <hidden>
Date: 2003-08-20 19:17:43
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On Wed, 20 Aug 2003, David S. Miller wrote:
On Wed, 20 Aug 2003 12:49:14 -0400 (EDT) Bill Davidsen [off-list ref] wrote:quoted
On 19 Aug 2003, Daniel Gryniewicz wrote: I have been asking for a similar thing as well, David mentioned some things that would break, but I believe they break if you use source routing, so that seems not to be a real objection.It's not about source routing. It's about failover and being able to use ARP on interfaces which don't have addresses assigned to them yet.
David mentioned that you could solve the problem by using *rp_filter and source routing. I don't think that's entirely true, but doing so has the same drawbacks and breaks the same things as a flag to make Linux behave like Sun/BSD/Windows (and work with Cisco is the cases previously mentioned).
quoted
I find it interesting that we can't change networking because a few complex systems would have to be reconfigured, but we *can* change modules which requires config changes on probably 90% of all systems (commercial distributions).Decisions about Networking will always be in a different domain because the way one behaves has effects upon other systems not just the local one.
Yes, that's exactly the point, the way Linux works has bad effects on certain other machines, as in leaves them disconnected to the Linux system.
BTW, another thing which makes the source address selection for outgoing ARPs a real touchy area is the following. Some weird configurations actually respond with different ARP answers based upon the source address in the ARP request. You can ask Julian Anastasov about such (arguably pathological) setups.
I don't think anyone is asking for a change in the default behaviour (although my point about breaking modules does apply), people would be satisfied, even ecstatic, if we had a simple way (flag) to set to make Linux work without setting /proc filters, using arpfilter, applying source routes (David's suggestion) and generally jumping through hoops. -- bill davidsen [off-list ref] CTO, TMR Associates, Inc Doing interesting things with little computers since 1979.