This post is the summary based on a recent discussion in the kernelnewbies mail list. Thanks to the collective intelligence, the Linux kernel ARP behavior with multiple NIC is now pretty clear.
0. Original Question
“Assume there are two interfaces eth0 and eth1 each configured with IPs belonging to different subnets. Say IP1 is assigned to eth0 and IP2 to eth1. Now if an ARP request comes on eth0 for IP2, what is the behavior on Linux?”
1. Summary
Without code checking, the answer comes from “Documentation/networking/ip-sysctl.txt” by looking at “/proc/sys/net/ipv4/conf/“
If IP1 and IP2 are in different subnets, as the question, arp_filter is the controller:
“0 – (default) The kernel can respond to arp requests with addresses from other interfaces. This may seem wrong but it usually makes sense, because it increases the chance of successful communication. IP addresses are owned by the complete host on Linux, not by particular interfaces. Only for more complex setups like load-balancing, does this behavior cause problems.“
If IP1 and IP2 are in the same subnets, arp_announce and arp_ignore are the controller.
davejingtian.org 
Now I am going away to do my breakfast, afterward
having my breakfast coming yet again to read other news.
Hmm it looks like your site ate my first comment (it was extremely long) so I guess I’ll just sum it up what
I had written and say, I’m thoroughly enjoying your blog.
I as well am an aspiring blog blogger but I’m still new
to everything. Do you have any helpful hints for inexperienced blog writers?
I’d genuinely appreciate it.
Hi there, of course this piece of writing is genuinely fastidious and I have learned lot of things from it regarding blogging.
thanks.
Hey! Do you know if they make any plugins to assist with SEO?
I’m trying to get my blog to rank for some targeted keywords but I’m not seeing very good success.
If you know of any please share. Cheers!
I like the helpful info you provide in your articles.
I will bookmark your weblog and check again here regularly.
I’m quite certain I’ll learn plenty of new stuff right here!
Best of luck for the next!
I have read so many articles or reviews on the topic of the
blogger lovers but this post is genuinely a pleasant piece of writing, keep it up., cari biro kontak jodoh http://tinyurl.com/q6jobk8
I think this is among the most vital info for
me. And i am glad reading your article. But
should remark on some general things, The website style is perfect, the
articles is really great : D. Good job, cheers
What’s up i am kavin, its my first occasion to commenting anywhere, when i read
this piece of writing i thought i could also make comment due to this
sensible piece of writing.