Repository
Munin (master)
Last change
2020-05-27
Graph Categories
Family
snmpauto
Capabilities
Language
Perl
License
GPL-2.0-only
Authors

snmp__if_multi

Name

snmp__if_multi - SNMP card plugin to monitor the network interfaces of any networked equipment.

Applicable Systems

Any SNMP capable networked computer equipment. Using a command such as “munin-node-configure –snmp switch.langfeldt.net –snmpversion 2c --snmpcommunity public | sh -x” should auto-detect all applicable interfaces. On a typical switch you will get one plugin pr. ethernet port. On a router you might get one plugin pr. VLAN interface.

Configuration

As a rule SNMP plugins need site specific configuration. The default configuration (shown here) will only work on insecure sites/devices:

[snmp_*]
     env.version 2
     env.community public
     env.ifTypeOnly ethernetCsmacd

In general SNMP is not very secure at all unless you use SNMP version 3 which supports authentication and privacy (encryption). But in any case the community string for your devices should not be “public”.

Please see ‘perldoc Munin::Plugin::SNMP’ for further configuration information.

The ifTypeOnly is a space separated list of media types to show. By default the plugin shows only interfaces identified as ‘ethernetCsmacd’. To see what interface types your switch, router, or other net thing uses you can use this command:

snmpwalk -c public -v 2c switch 1.3.6.1.2.1.2.2.1.3

It may show something like this:

IF-MIB::ifType.1 = INTEGER: ethernetCsmacd(6)
IF-MIB::ifType.4 = INTEGER: mplsTunnel(150)
IF-MIB::ifType.5 = INTEGER: other(1)
IF-MIB::ifType.6 = INTEGER: softwareLoopback(24)
IF-MIB::ifType.8 = INTEGER: tunnel(131)
IF-MIB::ifType.13 = INTEGER: propVirtual(53)
IF-MIB::ifType.123 = INTEGER: l2vlan(135)

propVirtual or l2vlan is usually used for VLAN interfaces. Tunnel would normally be for VPNs. A minor horde of different interface types are supposted, please see IANAifType-MIB (on your system or find with Google) for a full list.

Interpretation

The graph shows a stright forward “bits per second” incoming and outgoing thruput. “Incoming” is towards the monitored device.

Note: The internal representation of the speeds is in bytes pr. second. The plugin multiplies everything by 8 to get bits pr. second.

Mib Information

This plugin requires the IF-MIB the standard IETF MIB for network interfaces.

It reports the contents of the IF-MIB::ifHCInOctets/IF-MIB::ifHCOutOctets if available, IF-MIB::ifInOctets/IF-MIB::ifOutOctets if not. The former are 64 bit counters only available with SNMP 2 and later. The later are 32 bit counters (see FEATURES below).

For errors it reports ifInErrors + ifINDiscards and ifOutErrors + ifOutDiscards.

Magic Markers

#%# family=snmpauto
#%# capabilities=snmpconf

Bugs

Should support indexing by

- ifIndex
- ifName
- ifDescr
- ifAlias
- mac-address

(and anything else MRTG can index by) in addition to OID-index as now.

Pulling in a user definable set of ifName/ifDescr/ifAlias for textual description and even graph_title would also be nice.

If we get a patch to support the .oldname attribute then we may use that to let the operator change the indexing dynamically without data loss.

Features

You may get strange results if you use SNMPv1, or SNMPv2 on switches that do not support 64 bit byte counters. If the interface traffic exceeds about 50Mbps a 32 bit byte counter will wrap around in less than 5 minutes making the graph for the interface show random results.

If you have a switch/device that supports 64 bit byte counters this plugin will use them and the graph will be fine. The graph information will inform about this. You must use SNMPv2c or SNMPv3 to be able to use 64 bit counters - if the device supports them.

This problem is a feature of the device SNMP implementation or your usage of it, it is nothing the plugin can fix. In the future Munin may be able to run the plugin more often than the counter wraps around.

Author

Copyright (C) 2006-2010 Nicolai Langfeldt
Copyright (C) 2004-2005 Dagfinn Ilmari Mannsåker
Copyright (C) 2004 Jimmy Olsen

Based on the original snmp__if_ plugin written by Jimmy Olsen and Dagfinn Ilmari Mannsåker.

Reworked to snmp__if_multi by Nicolai Langfeldt.

License

GPLv2

Pod Errors

Hey! The above document had some coding errors, which are explained below:

  • Around line 122:

    Non-ASCII character seen before =encoding in ‘Mannsåker’. Assuming UTF-8

#!/usr/bin/perl -w

=head1 NAME

snmp__if_multi - SNMP card plugin to monitor the network interfaces of any networked equipment.

=head1 APPLICABLE SYSTEMS

Any SNMP capable networked computer equipment.  Using a command such
as "munin-node-configure --snmp switch.langfeldt.net --snmpversion 2c
--snmpcommunity public | sh -x" should auto-detect all applicable
interfaces.  On a typical switch you will get one plugin pr. ethernet
port.  On a router you might get one plugin pr. VLAN interface.

=head1 CONFIGURATION

As a rule SNMP plugins need site specific configuration.  The default
configuration (shown here) will only work on insecure sites/devices:

   [snmp_*]
	env.version 2
        env.community public
        env.ifTypeOnly ethernetCsmacd

In general SNMP is not very secure at all unless you use SNMP version
3 which supports authentication and privacy (encryption).  But in any
case the community string for your devices should not be "public".

Please see 'perldoc Munin::Plugin::SNMP' for further configuration
information.

The ifTypeOnly is a space separated list of media types to show.  By
default the plugin shows only interfaces identified as
'ethernetCsmacd'.  To see what interface types your switch, router, or
other net thing uses you can use this command:

  snmpwalk -c public -v 2c switch 1.3.6.1.2.1.2.2.1.3

It may show something like this:

  IF-MIB::ifType.1 = INTEGER: ethernetCsmacd(6)
  IF-MIB::ifType.4 = INTEGER: mplsTunnel(150)
  IF-MIB::ifType.5 = INTEGER: other(1)
  IF-MIB::ifType.6 = INTEGER: softwareLoopback(24)
  IF-MIB::ifType.8 = INTEGER: tunnel(131)
  IF-MIB::ifType.13 = INTEGER: propVirtual(53)
  IF-MIB::ifType.123 = INTEGER: l2vlan(135)

propVirtual or l2vlan is usually used for VLAN interfaces.  Tunnel
would normally be for VPNs.  A minor horde of different interface types
are supposted, please see IANAifType-MIB (on your system or find with
Google) for a full list.

=head1 INTERPRETATION

The graph shows a stright forward "bits per second" incoming and
outgoing thruput.  "Incoming" is towards the monitored device.

Note: The internal representation of the speeds is in bytes
pr. second.  The plugin multiplies everything by 8 to get bits
pr. second.

=head1 MIB INFORMATION

This plugin requires the IF-MIB the standard IETF MIB for network
interfaces.

It reports the contents of the
IF-MIB::ifHCInOctets/IF-MIB::ifHCOutOctets if available,
IF-MIB::ifInOctets/IF-MIB::ifOutOctets if not.  The former are 64 bit
counters only available with SNMP 2 and later.  The later are 32 bit
counters (see FEATURES below).

For errors it reports ifInErrors + ifINDiscards and ifOutErrors +
ifOutDiscards.

=head1 MAGIC MARKERS

  #%# family=snmpauto
  #%# capabilities=snmpconf

=head1 BUGS

Should support indexing by

  - ifIndex
  - ifName
  - ifDescr
  - ifAlias
  - mac-address

(and anything else MRTG can index by) in addition to OID-index as now.

Pulling in a user definable set of ifName/ifDescr/ifAlias for textual
description and even graph_title would also be nice.

If we get a patch to support the .oldname attribute then we may use
that to let the operator change the indexing dynamically without data
loss.

=head1 FEATURES

You may get strange results if you use SNMPv1, or SNMPv2 on
switches that do not support 64 bit byte counters.  If the interface
traffic exceeds about 50Mbps a 32 bit byte counter will wrap around in
less than 5 minutes making the graph for the interface show random
results.

If you have a switch/device that supports 64 bit byte counters this
plugin will use them and the graph will be fine.  The graph
information will inform about this.  You must use SNMPv2c or SNMPv3 to
be able to use 64 bit counters - if the device supports them.

This problem is a feature of the device SNMP implementation or your
usage of it, it is nothing the plugin can fix.  In the future Munin
may be able to run the plugin more often than the counter wraps
around.

=head1 AUTHOR

  Copyright (C) 2006-2010 Nicolai Langfeldt
  Copyright (C) 2004-2005 Dagfinn Ilmari Mannsåker
  Copyright (C) 2004 Jimmy Olsen

Based on the original snmp__if_ plugin written by Jimmy Olsen and
Dagfinn Ilmari Mannsåker.

Reworked to snmp__if_multi by Nicolai Langfeldt.

=head1 LICENSE

GPLv2

=cut

use strict;
use Munin::Plugin;
use Munin::Plugin::SNMP;

need_multigraph();


my $response;
my $iface;

# This is the snmpwalk:
# .1.3.6.1.2.1.2.1.0 = INTEGER: 2
# .1.3.6.1.2.1.2.2.1.1.1 = INTEGER: 1
# .1.3.6.1.2.1.2.2.1.1.65539 = INTEGER: 65539
# .1.3.6.1.2.1.2.2.1.2.1 = STRING: MS TCP Loopback interface
# .1.3.6.1.2.1.2.2.1.2.65539 = STRING: Broadcom NetXtreme Gigabit Ethernet
# .1.3.6.1.2.1.2.2.1.3.1 = INTEGER: softwareLoopback(24)
# .1.3.6.1.2.1.2.2.1.3.65539 = INTEGER: ethernetCsmacd(6)
# .1.3.6.1.2.1.2.2.1.4.1 = INTEGER: 1520
# .1.3.6.1.2.1.2.2.1.4.65539 = INTEGER: 1500
# .1.3.6.1.2.1.2.2.1.5.1 = Gauge32: 10000000
# .1.3.6.1.2.1.2.2.1.5.65539 = Gauge32: 1000000000
# .1.3.6.1.2.1.2.2.1.6.1 = STRING:
# .1.3.6.1.2.1.2.2.1.6.65539 = STRING: 0:30:48:75:65:5e
# .1.3.6.1.2.1.2.2.1.7.1 = INTEGER: up(1)
# .1.3.6.1.2.1.2.2.1.7.65539 = INTEGER: up(1)
# .1.3.6.1.2.1.2.2.1.8.1 = INTEGER: up(1)
# .1.3.6.1.2.1.2.2.1.8.65539 = INTEGER: up(1)
#
# 64 bit counters:
# .1.3.6.1.2.1.31.1.1.1.6.   Counter64 ifHCInOctets
# .1.3.6.1.2.1.31.1.1.1.10.  Counter64 ifHCOutOctets

if (defined $ARGV[0] and $ARGV[0] eq "snmpconf") {
	print "require 1.3.6.1.2.1.2.2.1.1.\n";
	exit 0;
}

my $sysDescr           = '1.3.6.1.2.1.1.1.0';
my $sysLocation        = '1.3.6.1.2.1.1.6.0';
my $sysContact         = '1.3.6.1.2.1.1.4.0';
my $sysName            = '1.3.6.1.2.1.1.5.0';

my $ifOIDBase          = "1.3.6.1.2.1.2.2.1";		# ifEntry
my $ifv2OIDBase        = "1.3.6.1.2.1.31.1.1.1";	# ifXEntry

my %ifTypes = (
    other => 1,
    regular1822 => 2,
    hdh1822 => 3,
    ddnX25 => 4,
    rfc877x25 => 5,
    ethernetCsmacd => 6,
    iso88023Csmacd => 7,
    iso88024TokenBus => 8,
    iso88025TokenRing => 9,
    iso88026Man => 10,
    starLan => 11,
    proteon10Mbit => 12,
    proteon80Mbit => 13,
    hyperchannel => 14,
    fddi => 15,
    lapb => 16,
    sdlc => 17,
    ds1 => 18,
    e1 => 19,
    basicISDN => 20,
    primaryISDN => 21,
    propPointToPointSerial => 22,
    ppp => 23,
    softwareLoopback => 24,
    eon => 25,
    ethernet3Mbit => 26,
    nsip => 27,
    slip => 28,
    ultra => 29,
    ds3 => 30,
    sip => 31,
    frameRelay => 32,
    rs232 => 33,
    para => 34,
    arcnet => 35,
    arcnetPlus => 36,
    atm => 37,
    miox25 => 38,
    sonet => 39,
    x25ple => 40,
    iso88022llc => 41,
    localTalk => 42,
    smdsDxi => 43,
    frameRelayService => 44,
    v35 => 45,
    hssi => 46,
    hippi => 47,
    modem => 48,
    aal5 => 49,
    sonetPath => 50,
    sonetVT => 51,
    smdsIcip => 52,
    propVirtual => 53,
    propMultiplexor => 54,
    ieee80212 => 55,
    fibreChannel => 56,
    hippiInterface => 57,
    frameRelayInterconnect => 58,
    aflane8023 => 59,
    aflane8025 => 60,
    cctEmul => 61,
    fastEther => 62,
    isdn => 63,
    v11 => 64,
    v36 => 65,
    g703at64k => 66,
    g703at2mb => 67,
    qllc => 68,
    fastEtherFX => 69,
    channel => 70,
    ieee80211 => 71,
    ibm370parChan => 72,
    escon => 73,
    dlsw => 74,
    isdns => 75,
    isdnu => 76,
    lapd => 77,
    ipSwitch => 78,
    rsrb => 79,
    atmLogical => 80,
    ds0 => 81,
    ds0Bundle => 82,
    bsc => 83,
    async => 84,
    cnr => 85,
    iso88025Dtr => 86,
    eplrs => 87,
    arap => 88,
    propCnls => 89,
    hostPad => 90,
    termPad => 91,
    frameRelayMPI => 92,
    x213 => 93,
    adsl => 94,
    radsl => 95,
    sdsl => 96,
    vdsl => 97,
    iso88025CRFPInt => 98,
    myrinet => 99,
    voiceEM => 100,
    voiceFXO => 101,
    voiceFXS => 102,
    voiceEncap => 103,
    voiceOverIp => 104,
    atmDxi => 105,
    atmFuni => 106,
    atmIma => 107,
    pppMultilinkBundle => 108,
    ipOverCdlc => 109,
    ipOverClaw => 110,
    stackToStack => 111,
    virtualIpAddress => 112,
    mpc => 113,
    ipOverAtm => 114,
    iso88025Fiber => 115,
    tdlc => 116,
    gigabitEthernet => 117,
    hdlc => 118,
    lapf => 119,
    v37 => 120,
    x25mlp => 121,
    x25huntGroup => 122,
    trasnpHdlc => 123,
    interleave => 124,
    fast => 125,
    ip => 126,
    docsCableMaclayer => 127,
    docsCableDownstream => 128,
    docsCableUpstream => 129,
    a12MppSwitch => 130,
    tunnel => 131,
    coffee => 132,
    ces => 133,
    atmSubInterface => 134,
    l2vlan => 135,
    l3ipvlan => 136,
    l3ipxvlan => 137,
    digitalPowerline => 138,
    mediaMailOverIp => 139,
    dtm => 140,
    dcn => 141,
    ipForward => 142,
    msdsl => 143,
    ieee1394 => 144,
    'if-gsn' => 145,
    dvbRccMacLayer => 146,
    dvbRccDownstream => 147,
    dvbRccUpstream => 148,
    atmVirtual => 149,
    mplsTunnel => 150,
    srp => 151,
    voiceOverAtm => 152,
    voiceOverFrameRelay => 153,
    idsl => 154,
    compositeLink => 155,
    ss7SigLink => 156,
    propWirelessP2P => 157,
    frForward => 158,
    rfc1483 => 159,
    usb => 160,
    ieee8023adLag => 161,
    bgppolicyaccounting => 162,
    frf16MfrBundle => 163,
    h323Gatekeeper => 164,
    h323Proxy => 165,
    mpls => 166,
    mfSigLink => 167,
    hdsl2 => 168,
    shdsl => 169,
    ds1FDL => 170,
    pos => 171,
    dvbAsiIn => 172,
    dvbAsiOut => 173,
    plc => 174,
    nfas => 175,
    tr008 => 176,
    gr303RDT => 177,
    gr303IDT => 178,
    isup => 179,
    propDocsWirelessMaclayer => 180,
    propDocsWirelessDownstream => 181,
    propDocsWirelessUpstream => 182,
    hiperlan2 => 183,
    propBWAp2Mp => 184,
    sonetOverheadChannel => 185,
    digitalWrapperOverheadChannel => 186,
    aal2 => 187,
    radioMAC => 188,
    atmRadio => 189,
    imt => 190,
    mvl => 191,
    reachDSL => 192,
    frDlciEndPt => 193,
    atmVciEndPt => 194,
    opticalChannel => 195,
    opticalTransport => 196,
    propAtm => 197,
    voiceOverCable => 198,
    infiniband => 199,
    teLink => 200,
    q2931 => 201,
    virtualTg => 202,
    sipTg => 203,
    sipSig => 204,
    docsCableUpstreamChannel => 205,
    econet => 206,
    pon155 => 207,
    pon622 => 208,
    bridge => 209,
    linegroup => 210,
    voiceEMFGD => 211,
    voiceFGDEANA => 212,
    voiceDID => 213,
    mpegTransport => 214,
    sixToFour => 215,
    gtp => 216,
    pdnEtherLoop1 => 217,
    pdnEtherLoop2 => 218,
    opticalChannelGroup => 219,
    homepna => 220,
    gfp => 221,
    ciscoISLvlan => 222,
    actelisMetaLOOP => 223,
    fcipLink => 224,
    rpr => 225,
    qam => 226,
    lmp => 227,
    cblVectaStar => 228,
    docsCableMCmtsDownstream => 229,
    adsl2 => 230,
    macSecControlledIF => 231,
    macSecUncontrolledIF => 232,
    aviciOpticalEther => 233,
    atmbond => 234,
    voiceFGDOS => 235,
    mocaVersion1 => 236,
    ieee80216WMAN => 237,
    adsl2plus => 238,
    dvbRcsMacLayer => 239,
    dvbTdm => 240,
    dvbRcsTdma => 241,
    x86Laps => 242,
    wwanPP => 243,
    wwanPP2 => 244
    );

my %ifTypeByNum = map { $ifTypes{$_} => $_; } keys %ifTypes;

# Needed as globals
my $snmpinfo;
my $snmpinfoX;

sub do_collect {
    # Collect information from SNMP agent

    my $session = Munin::Plugin::SNMP->session();

    $snmpinfo = $session->get_hash(
	-baseoid => $ifOIDBase,
	-cols    =>
	{ 2  => 'ifDescr',
	  # Type: See above
	  3  => 'ifType',
	  4  => 'ifMtu',
	  5  => 'ifSpeed',
	  6  => 'ifMac',
	  7  => 'ifAdminStatus',
	  # Oper: 1) up 2) down 3) testing
	  # 4) unknown, 5) dormant 6) not present
	  # 7) lowerLayerDown
	  8  => 'ifOperStatus',
	  10 => 'ifInOctets',
	  11 => 'ifInUcastPkts',
	  13 => 'ifInDiscards',
	  14 => 'ifInErrors',
	  15 => 'ifUnUnknownProtos',
	  16 => 'ifOutOctets',
	  18 => 'ifOutNUcastPkts',
	  19 => 'ifOutDiscards',
	  20 => 'ifOutErrors',
	});

    # ifXEntry - SNMP v2 and up only - on some devices
    $snmpinfoX = $session->get_hash(
	-baseoid => $ifv2OIDBase,
	-cols    =>
	{ 1  => 'ifName',
	  2  => 'ifInMulticastPkts',
	  3  => 'ifInBroadcastPkts',
	  4  => 'ifOutMulticastPkts',
	  5  => 'ifOutBroadcastPkts',
	  6  => 'ifHCInOctets',
	  10 => 'ifHCOutOctets',
	  15 => 'ifHighSpeed',
	  18 => 'ifAlias',
	});
}



sub do_preprocess_if {
    my ($mediatype, $if) = @_;

    my $response = $snmpinfo->{$if}->{ifType} || 1;

    if (defined($mediatype)) {
	if (defined($mediatype->{$response})) {
	    # This is one of the interesting media types
	} else {
	    # This media type is not interesting.  Remove.
	    delete $snmpinfo->{$if} if exists $snmpinfo->{$if};
	    delete $snmpinfoX->{$if} if exists $snmpinfoX->{$if};
	    return;
	}
    }

    if (defined ($response = $snmpinfo->{$if}->{ifOperStatus})) {
	# 1 = up,  2 = down,  7 = lowerLayerDown
	if ($response == 2 or $response == 7) {
	    # Fold recognized down states into one.
	    $response = $snmpinfo->{$if}->{ifOperStatus} = 2;
	} elsif ($response != 1) {
	    # This interface is fishy, remove and forget.
	    delete $snmpinfo->{$if} if exists $snmpinfo->{$if};
	    delete $snmpinfoX->{$if} if exists $snmpinfoX->{$if};
	    return;
	}
    }
}


sub do_preprocess {
    my $mediatypes = 'ethernetCsmacd';

    if (exists( $ENV{'ifTypeOnly'} )) {
	$mediatypes = $ENV{'ifTypeOnly'};
    }

    my @mediatypes = split(/[ ,]+/,$mediatypes);

    # Hash of numerical media types the user finds interesting.
    my $mediatype={};

    if ($mediatypes eq 'ALL') {
	$mediatype = undef;
    } else {
	foreach my $type (@mediatypes) {
	    if (exists($ifTypes{$type})) {
		$mediatype->{$ifTypes{$type}} = 1;
	    } else {
		die "Unknown media type '$type' specified in ifTypeOnly\n";
	    }
	}
    }

    foreach my $if (keys %{$snmpinfo}) {
	do_preprocess_if($mediatype, $if);
    }
}


sub do_config_root {
    my ($host) = @_;

    print "multigraph if_bytes\n";
    print "graph_title All interfaces traffic\n";
    print "graph_order recv send\n";
    print "graph_args --base 1000\n";
    print "graph_vlabel bits in (-) / out (+) per \${graph_period}\n";
    print "graph_category network\n";
    print "graph_info This graph shows the total traffic for $host\n";

    print "send.info Bits sent/received by $host\n";
    print "recv.label recv\n";
    print "recv.type DERIVE\n";
    print "recv.graph no\n";
    print "recv.cdef recv,8,*\n";
    print "recv.min 0\n";
    print "send.label bps\n";
    print "send.type DERIVE\n";
    print "send.negative recv\n";
    print "send.cdef send,8,*\n";
    print "send.min 0\n";

    print "multigraph if_errors\n";
    print "graph_title All interfaces errors\n";
    print "graph_order recv send\n";
    print "graph_scale no\n";
    print "graph_args --base 1000\n";
    print "graph_vlabel errors in (-) / out (+) per \${graph_period}\n";
    print "graph_category network\n";
    print "graph_info This graph shows the total errors for $host\n";

    print "send.info Errors in outgoing/incoming traffic on $host\n";
    print "recv.label recv\n";
    print "recv.type DERIVE\n";
    print "recv.graph no\n";
    print "recv.min 0\n";
    print "send.label Errors\n";
    print "send.type DERIVE\n";
    print "send.negative recv\n";
    print "send.min 0\n";
}


sub do_config_if {
    my ($host,$version,$if) = @_;

    my $alias = $snmpinfoX->{$if}->{ifName} || "$if";

    if ($snmpinfoX->{$if}->{ifAlias}) {
        $alias .= " ($snmpinfoX->{$if}->{ifAlias})";
    } else {
        $alias .= " ($snmpinfo->{$if}->{ifDescr})";
    }

    my $extrainfo = '';

    if (defined ($response = $snmpinfo->{$if}->{ifOperStatus})) {
	if ($response == 2) {
	    # Interface is down
	    $extrainfo .= ' The interface is currently down.'
	}
    }

    my $warn = undef;
    my $speed = 0;

    if (defined ($speed = $snmpinfoX->{$if}->{ifHighSpeed}) and $speed) {
      # Speed in 1,000,000 bits per second
      $speed = $speed * 1000000;
      $warn = $speed * 75 / 100;

      my $textspeed = scaleNumber($speed,'bps','',
				  'The interface speed is %.1f%s%s.');

      $extrainfo .= ' '.$textspeed if $textspeed;
    } elsif (defined ($speed = $snmpinfo->{$if}->{ifSpeed}) and $speed) {
        # Speed in bits pr. second
	$warn = $speed/100*75;

	my $textspeed = scaleNumber($speed,'bps','',
				    'The interface speed is %.1f%s%s.');

	$extrainfo .= " ".$textspeed if $textspeed;
    }

    if (defined ($snmpinfoX->{$if}->{ifHCInOctets})) {
	# If we get an answer at the 64 bit OID then this switch
	# supports the extended MIB

	$extrainfo .= " This switch supports 64 bit byte counters and these are used by this plugin.";
    } else {
	# If not we only have a 32 bit counter and are lost.
	$extrainfo .= " NOTE! This switch supports only 32 bit byte counters which makes the plugin unreliable and unsuitable for most 100Mb (or faster) interfaces, where bursts are expected to exceed 50Mbps.  This means that for interfaces where much traffic is sent this plugin will report false thruputs and cannot be trusted.";

	# unless perhaps the operator can get us snmp version 2c or 3?
	$extrainfo .= " I notice that you use SNMP version 1 which does not support 64 bit quantities.  You may get better results if you switch to SNMP version 2c or 3.  Please refer to the plugin documentation."
	  if $version == 1;
    }

    $response = $snmpinfo->{$if}->{ifType};
    $extrainfo .= " This is a '".$ifTypeByNum{$response}."' interface.";

    print "multigraph if_bytes.if_$if\n";

    print "graph_title $alias traffic\n";
    print "graph_order recv send\n";
    print "graph_args --base 1000\n";
    print "graph_vlabel bits in (-) / out (+) per \${graph_period}\n";
    print "graph_category network\n";
    print "graph_info This graph shows traffic for the \"$alias\" network interface.$extrainfo\n";
    print "send.info Bits sent/received by this interface.\n";
    print "recv.label recv\n";
    print "recv.type DERIVE\n";
    print "recv.graph no\n";
    print "recv.cdef recv,8,*\n";
    print "recv.max $speed\n" if $speed;
    print "recv.min 0\n";
    print "recv.warning $warn\n" if defined $warn;
    print "send.label bps\n";
    print "send.type DERIVE\n";
    print "send.negative recv\n";
    print "send.cdef send,8,*\n";
    print "send.max $speed\n" if $speed;
    print "send.min 0\n";
    print "send.warning $warn\n" if defined $warn;

    print "multigraph if_errors.if_$if\n";

    print "graph_title $alias errors\n";
    print "graph_order recv send\n";
    print "graph_args --base 1000\n";
    print "graph_scale no\n";
    print "graph_vlabel errors in (-) / out (+) per \${graph_period}\n";
    print "graph_category network\n";
    print "graph_info This graph shows errors for the \"$alias\" network interface.$extrainfo\n";
    print "send.info Errors in outgoing/incoming traffic on this interface.\n";
    print "recv.label recv\n";
    print "recv.type DERIVE\n";
    print "recv.graph no\n";
    print "recv.min 0\n";
    print "recv.warning 1\n";
    print "send.label errors\n";
    print "send.type DERIVE\n";
    print "send.negative recv\n";
    print "send.min 0\n";
    print "send.warning 1\n";
}


sub do_fetch_root {
    # Construct root graphs for the if_bytes and if_error spaces

    my $in = 0;
    my $out = 0;
    my $inerr = 0;
    my $outerr = 0;

    foreach my $if (keys %{$snmpinfo}) {
	# Do not take interface up or down-ness into account, the
	# interface counters are not reset when the interface goes up
	# so we must always account for all interfaces.

	# But note that do_fetch_if has previously removed all
	# interfaces with a "fishy" status.  That is a possible bug.
	# Or a feature.  We'll see.

	$in += $snmpinfoX->{$if}->{ifHCInOctets} || $snmpinfo->{$if}->{ifInOctets} || 0;
	$out += $snmpinfoX->{$if}->{ifHCOutOctets} || $snmpinfo->{$if}->{ifOutOctets} || 0;
	$inerr += $snmpinfoX->{$if}->{ifInErrors} || $snmpinfo->{$if}->{ifInDiscards} || 0;
	$outerr += $snmpinfoX->{$if}->{ifOutErrors} || $snmpinfo->{$if}->{ifOutDiscards} || 0;

    }

    print "multigraph if_bytes\n";
    print "recv.value $in\n";
    print "send.value $out\n";

    print "multigraph if_errors\n";
    print "recv.value $inerr\n";
    print "send.value $outerr\n";
}


sub do_fetch_if {
    my($if) = @_;

    my $status = $snmpinfo->{$if}->{ifOperStatus} || 1;

    my $response;

    # 1 means up
    # 2 means set to down
    # Everything else we ignore.

    print "multigraph if_bytes.if_$if\n";

    if ($status == 2) {
	# Interface is down
	print "recv.value U\n";
	print "send.value U\n";
	print "send.extinfo This interface is currently down.\n";
	goto if_errors;
    }

    if (defined ($response = $snmpinfoX->{$if}->{ifHCInOctets} ||
		 $snmpinfo->{$if}->{ifInOctets})) {
	print "recv.value ", $response, "\n";
    } else {
	# No response...
	print "recv.value U\n";
   }

    if (defined ($response = $snmpinfoX->{$if}->{ifHCOutOctets} ||
		 $snmpinfo->{$if}->{ifOutOctets})) {
	print "send.value ", $response, "\n";
    } else {
	# No response...
	print "send.value U\n";
    }

  if_errors:

    print "multigraph if_errors.if_$if\n";

    if ($status == 2) {
	print "recv.value U\n";
	print "send.value U\n";
	print "send.extinfo This interface is down\n";
	return;
    }

    $response = ( $snmpinfo->{$if}->{ifInErrors} || 0 ) +
      ( $snmpinfo->{$if}->{ifInDiscards} || 0 );

    print "recv.value $response\n";

    $response = ( $snmpinfo->{$if}->{ifOutErrors} || 0 ) +
      ( $snmpinfo->{$if}->{ifOutDiscards} || 0 );

    print "send.value $response\n";
}


sub do_config {

    my ($host,undef,$version) = Munin::Plugin::SNMP->config_session();

    print "host_name $host\n" unless $host eq 'localhost';

    # Also do overview graph with all ports summarized
    foreach my $if (sort {$a <=> $b} keys %{$snmpinfo}) {
	do_config_if($host,$version,$if);
    }

    do_config_root($host);
}


sub do_fetch {
    # Also do overview graph with all ports summarized and collected
    # meta information in graph_info.
    # Add to this error graphs and so on.  And meta information about
    # interface type.

    foreach my $if (sort {$a <=> $b} keys %{$snmpinfo}) {
	do_fetch_if($if);
    }
    do_fetch_root();
}

# ############################## MAIN ################################

do_collect;
do_preprocess;

if ($ARGV[0] and $ARGV[0] eq "config") {
    do_config();
    exit 0;
}

do_fetch();