William Herrin <[email protected]> writes: > On Wed, Jun 5, 2013 at 6:25 PM, Ricky Beam <[email protected]> wrote: >> I won't argue against calling Linux "wrong". However, the linux way of >> dealing with ARP is well tuned for "host" and not "router" duty. > > I love Linux and use it throughout my work but I can't tell you the > number of times its ARP behavior has bitten me. If you send a packet > to a VIP on a Linux box and it doesn't have an arp entry for the > default gateway, the Linux box will send an arp request... with the > vip as the source. That is just wrong. Wrong, wrong, wrong. Use the > damn interface IP when you arp for something on that interface. If the > router doesn't happen to like the bad arp (since the VIP isn't on the > router's LAN) the router will ignore it. And your service will merrily > pop up and down depending on whether the Linux box has any traffic to > originate.
Did you try setting sys.net.ipv4.conf.all.arp_announce=2 ? Yes, the system default may be tuned for host/desktop usage, but it's not like you *have* to use the system default. Tweak it as you like. And if there isn't enough knobs, then you can always add another one. You have the source code. Bjørn
