Date: Fri, 16 Mar 2018 14:47:34 +0100 (CET) From: sthaug@nethelp.no To: "Andrey V. Elsukov" <bu7cher@yandex.ru> Cc: melifaro@ipfw.ru, freebsd-net@freebsd.org Subject: Re: Does FreeBSD do proactive ARP refresh?,Re: Does FreeBSD do proactive ARP refresh? Message-ID: <20180316.144734.78772139.sthaug@nethelp.no> In-Reply-To: <21eca372-6fc0-6c86-4ca8-a398bfa37d92@yandex.ru> References: <20180316.122720.71152047.sthaug@nethelp.no> <20180316.124748.104098359.sthaug@nethelp.no> <21eca372-6fc0-6c86-4ca8-a398bfa37d92@yandex.ru>
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> >> And thank you for that suggestion! The packet loss during ARP refresh
> >> (of the destination address connected to the output interface) does
> >> *not* happen when the box is forwarding! It only happens with locally
> >> generated traffic.
> >
> > Checking once per second with "arp -n <destination IP>" I can see the
> > following behavior with net.link.ether.inet.max_age=120:
> >
> > - Locally generated traffic: The ARP entry is refreshed after
> > net.link.ether.inet.max_age seconds - which presumably means it
> > actually expires first. And there is some packet loss.
> >
> > - Transit traffic (the box is forwarding): The ARP entry is refreshed
> > 5 seconds *before* net.link.ether.inet.max_age has passed, and there
> > is no packet loss.
>
> Can you test this patch? I did not tested it, but I think it should fix
> this issue.
Looks like this is a patch against HEAD. I don't have any boxes
running HEAD, but I can get one installed and test the patch this
weekend (unless you want to produce a patch against 11.1-STABLE).
I tried the patch manually applied on 11.1-STABLE, but got lots of
errors during kernel compilation (see the end of this message).
Steinar Haug, Nethelp consulting, sthaug@nethelp.no
----------------------------------------------------------------------
cc -c -O2 -pipe -fno-strict-aliasing -g -nostdinc -I. -I../../.. -I../../../contrib/libfdt -D_KERNEL -DHAVE_KERNEL_OPTION_HEADERS -include opt_global.h -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -MD -MF.depend.if_ethersubr.o -MTif_ethersubr.o -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float -fno-asynchronous-unwind-tables -ffreestanding -fwrapv -fstack-protector -gdwarf-2 -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual -Wundef -Wno-pointer-sign -D__printf__=__freebsd_kprintf__ -Wmissing-include-dirs -fdiagnostics-show-option -Wno-unknown-pragmas -Wno-error-tautological-compare -Wno-error-empty-body -Wno-error-parentheses-equality -Wno-error-unused-function -Wno-error-pointer-sign -Wno-error-shift-negative-value -Wno-error-address-of-packed-member -mno-aes -mno-avx -std=iso9899:1999 -Werror ../../../net/if_ethersubr.c
../../../net/if_ethersubr.c:288:18: error: unused variable 't' [-Werror,-Wunused-variable]
struct pf_mtag *t;
^
../../../net/if_ethersubr.c:286:7: error: unused variable 'linkhdr' [-Werror,-Wunused-variable]
char linkhdr[ETHER_HDR_LEN], *phdr;
^
../../../net/if_ethersubr.c:285:6: error: unused variable 'error' [-Werror,-Wunused-variable]
int error = 0;
^
../../../net/if_ethersubr.c:289:6: error: unused variable 'loop_copy' [-Werror,-Wunused-variable]
int loop_copy = 1;
^
../../../net/if_ethersubr.c:287:23: error: unused variable 'eh' [-Werror,-Wunused-variable]
struct ether_header *eh;
^
../../../net/if_ethersubr.c:293:18: error: unused variable 'rt0' [-Werror,-Wunused-variable]
struct rtentry *rt0 = NULL;
^
../../../net/if_ethersubr.c:335:4: error: control reaches end of non-void function [-Werror,-Wreturn-type]
}
^
../../../net/if_ethersubr.c:336:3: error: extraneous closing brace ('}')
}
^
../../../net/if_ethersubr.c:337:3: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
rt0 = ro->ro_rt;
^
../../../net/if_ethersubr.c:337:9: error: use of undeclared identifier 'ro'
rt0 = ro->ro_rt;
^
../../../net/if_ethersubr.c:338:2: error: extraneous closing brace ('}')
}
^
../../../net/if_ethersubr.c:341:2: error: type specifier missing, defaults to 'int' [-Werror,-Wimplicit-int]
error = mac_ifnet_check_transmit(ifp, m);
^
../../../net/if_ethersubr.c:341:35: error: use of undeclared identifier 'ifp'
error = mac_ifnet_check_transmit(ifp, m);
^
../../../net/if_ethersubr.c:341:40: error: use of undeclared identifier 'm'
error = mac_ifnet_check_transmit(ifp, m);
^
../../../net/if_ethersubr.c:342:2: error: expected identifier or '('
if (error)
^
../../../net/if_ethersubr.c:343:3: error: expected identifier or '('
senderr(error);
^
../../../net/if_ethersubr.c:123:49: note: expanded from macro 'senderr'
#define senderr(e) do { error = (e); goto bad;} while (0)
^
../../../net/if_ethersubr.c:347:2: error: expected identifier or '('
if (ifp->if_flags & IFF_MONITOR)
^
../../../net/if_ethersubr.c:348:3: error: expected identifier or '('
senderr(ENETDOWN);
^
../../../net/if_ethersubr.c:123:49: note: expanded from macro 'senderr'
#define senderr(e) do { error = (e); goto bad;} while (0)
^
../../../net/if_ethersubr.c:349:2: error: expected identifier or '('
if (!((ifp->if_flags & IFF_UP) &&
^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.
*** Error code 1
Stop.
make: stopped in /usr/src/sys/amd64/compile/DNS_VIMAGE
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