Eugene Grosbein wrote:
Hi!I've just found that ports/net-snmp (version 5.4) built WITH_MFD_REWRITES=yes supports IF-MIB, and in theory should show 64-bit ifHC* counters but it does not. It seems agent/mibgroup/if-mib/data_access/interface_sysctl.c that obtains interface statistics from the kernel. The function netsnmp_arch_interface_container_load() has the following code: /* get counters */ entry->stats.ibytes.low = ifp->ifm_data.ifi_ibytes; entry->stats.ibytes.high = 0; entry->stats.iucast.low = ifp->ifm_data.ifi_ipackets; entry->stats.iucast.high = 0; entry->stats.imcast.low = ifp->ifm_data.ifi_imcasts; entry->stats.imcast.high = 0; So, it always produce 32-bit quantities. My question is: does FreeBSD/i386 kernel maintain 64-bit counters for interface statictics these days? If yes, since what version?
It does not, because not all architectures have atomic 64-bit increments and adds. Implementing 64-bit counters on these architectures would require some kind of locking. This was discussed in the past.
You might look at the IF-MIB implementation of bsnmp (it is in the base system). It uses periodic polling to detect wraps of the 32-bit counters. The poll interval is tuned to the fastest interface in the system (given that all interfaces reported the correct speed).
Note, that the netsnmp implementation is plain wrong - if the daemon does not support the HC counters it should never pretend to do. This is explicitely stated somewhere in the RFCs.
harti _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"
