Date: Tue, 16 Dec 2008 19:22:45 +0100 (CET) From: Harti Brandt <hartmut.brandt@dlr.de> To: Bruce Simpson <bms@incunabulum.net> Cc: freebsd-net@freebsd.org, Sergey Matveychuk <sem@FreeBSD.org> Subject: Re: bsnmpd & 64bits counters problem Message-ID: <20081216191244.C74416@beagle.kn.op.dlr.de> In-Reply-To: <4947EEA5.6050501@incunabulum.net> References: <4947D7A9.2050407@FreeBSD.org> <20081216181850.O74416@beagle.kn.op.dlr.de> <4947EEA5.6050501@incunabulum.net>
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On Tue, 16 Dec 2008, Bruce Simpson wrote: BS>Harti Brandt wrote: BS>> The highspeed counters are only there if this is a high-speed interface. BS>> High speed means that the baudrate in the interface MIB (the one in the BS>> kernel) must be larger than 20Mbaud. BS>> BS> BS>Does it look at the if_baudrate member? BS> BS>em(4) and other drivers will set if_baudrate according to the speed detected BS>from Ethernet link beat, this could be creating a situation where bsnmpd is BS>not exposing the high-speed counters at runtime? BS> BS>I imagine this could really confuse an SNMP-oriented Network Management BS>System such as Nagios or OpenNMS. Yes, it looks at ifi_baudrate. The reason is that the HC counters are mandatory only for interfaces with > 20MBit/second according to the compliance statememnt of the MIB. The HC counters come add additional cost, because the daemon has to poll the kernel's 32 bit counters and detect wrap arounds. So the daemon adapts dynamically based on the interface with the highest speed. And in any case, network management tools must be prepared to handle both cases. See also RFC2233: For interfaces that operate at 20,000,000 (20 million) bits per second or less, 32-bit byte and packet counters MUST be used. harti
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