On Fri, May 04, 2007 at 05:48:18AM +0200, Øyvind Vågen Jægtnes wrote: > Hi again :) > > On 5/4/07, Willy Tarreau <[EMAIL PROTECTED]> wrote: > >On Thu, May 03, 2007 at 11:12:09PM +0200, Øyvind Vågen Jægtnes wrote: > >> On 5/3/07, Jan Engelhardt <[EMAIL PROTECTED]> wrote: > >> > > >> >On May 3 2007 22:53, Willy Tarreau wrote: > >> >>> For the rest all we see in the arp cache is (incomplete) > >> >> > >> >>I suspect that your arp cache is full (128 entries by default). > >> >>Check /proc/sys/net/ipv4/neigh/gc_thresh1 (128 for me). You can > >> >>set it as high as gc_thresh2 (512 for me), and I don't know what > >> >>happens above. > >> > > >> >Above, you will perhaps need the not-so-elegant userspace arpd :-/ > >> > >> Yes, i was suspecting that the arp cache got full, but i will try > >> increasing it :) > >> Would there be any huge bugs if i change these lines in arp.c: > >> > >> .gc_thresh1 = 128, > >> .gc_thresh2 = 512, > >> > >> to > >> > >> .gc_thresh1 = 700, > >> .gc_thresh2 = 700, > >> > >> under the definition for struct arp_tbl? > > > >I don't think it could cause a problem, but network people will surely > >correct me if I'm wrong. > > System is up and running perfectly now, it is routing everything at > about 200 mbps now with only 5% load avg with the above changes to > arp.c > > So the real question now is, why is this number so low by default? > It would probably be much better if this could be handled dynamically > in the kernel.
I remember I read an argument against this a long time ago, but I don't remember where. I think it was some arbitrary decision that people using more than X ARP entries will need arpd. Most probably the code path in the ARP updates is/was not much optimized to handle large number of entries. Think about cable operators who may have 10-20000 entries ! > Its a Juniper M7i > It comes default with a 5400 rpm laptop 2.5" harddrive but now we > bought a more robust "server" 2.5" harddrive. The "server" ones are not necessarily more robust, often they are faster. > It still barfs on the OS > install, so the linux is doing all the job now. Will get a juniper guy > to come and fix :) > > As a side note, i'm starting to wonder if it was worth the $20k when i > could just have a linux machine to do the job with a clone for backup > ;) That's often how linux penetrates the enterprise ;-) Willy - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
