
# Linux by SNMP

## Overview

For Zabbix version: 6.0 and higher.  

## Setup

Install snmpd agent on Linux OS, enable SNMPv2.  

Make sure access to UCD-SNMP-MIB is allowed from Zabbix server/proxy host, since,  
by default, snmpd (for example, in Ubuntu) limits access to basic system information only:

```text
rocommunity public  default    -V systemonly
```

Make sure you change that in order to read metrics of UCD-SNMP-MIB and UCD-DISKIO-MIB. Please refer to the documentation:  
http://www.net-snmp.org/wiki/index.php/Vacm  

You can also try to use `snmpconf`:
  
http://www.net-snmp.org/wiki/index.php/TUT:snmpd_configuration

Change {$SNMP_COMMUNITY} on the host level in Zabbix.


## Zabbix configuration

No specific Zabbix configuration is required.

### Macros used

|Name|Description|Default|
|----|-----------|-------|
|{$CPU.UTIL.CRIT} |<p>-</p> |`90` |
|{$ICMP_LOSS_WARN} |<p>-</p> |`20` |
|{$ICMP_RESPONSE_TIME_WARN} |<p>-</p> |`0.15` |
|{$IF.ERRORS.WARN} |<p>-</p> |`2` |
|{$IF.UTIL.MAX} |<p>-</p> |`90` |
|{$IFCONTROL} |<p>-</p> |`1` |
|{$LOAD_AVG_PER_CPU.MAX.WARN} |<p>Load per CPU considered sustainable. Tune if needed.</p> |`1.5` |
|{$MEMORY.AVAILABLE.MIN} |<p>-</p> |`20M` |
|{$MEMORY.UTIL.MAX} |<p>-</p> |`90` |
|{$NET.IF.IFADMINSTATUS.MATCHES} |<p>Ignore notPresent(6)</p> |`^.*` |
|{$NET.IF.IFADMINSTATUS.NOT_MATCHES} |<p>Ignore down(2) administrative status</p> |`^2$` |
|{$NET.IF.IFALIAS.MATCHES} |<p>-</p> |`.*` |
|{$NET.IF.IFALIAS.NOT_MATCHES} |<p>-</p> |`CHANGE_IF_NEEDED` |
|{$NET.IF.IFDESCR.MATCHES} |<p>-</p> |`.*` |
|{$NET.IF.IFDESCR.NOT_MATCHES} |<p>-</p> |`CHANGE_IF_NEEDED` |
|{$NET.IF.IFNAME.MATCHES} |<p>-</p> |`^.*$` |
|{$NET.IF.IFNAME.NOT_MATCHES} |<p>Filter out loopbacks, nulls, docker veth links and docker0 bridge by default</p> |`(^Software Loopback Interface|^NULL[0-9.]*$|^[Ll]o[0-9.]*$|^[Ss]ystem$|^Nu[0-9.]*$|^veth[0-9a-z]+$|docker[0-9]+|br-[a-z0-9]{12})` |
|{$NET.IF.IFOPERSTATUS.MATCHES} |<p>-</p> |`^.*$` |
|{$NET.IF.IFOPERSTATUS.NOT_MATCHES} |<p>Ignore notPresent(6)</p> |`^6$` |
|{$NET.IF.IFTYPE.MATCHES} |<p>-</p> |`.*` |
|{$NET.IF.IFTYPE.NOT_MATCHES} |<p>-</p> |`CHANGE_IF_NEEDED` |
|{$SNMP.TIMEOUT} |<p>-</p> |`5m` |
|{$SWAP.PFREE.MIN.WARN} |<p>-</p> |`50` |
|{$VFS.DEV.DEVNAME.MATCHES} |<p>This macro is used in block devices discovery. Can be overridden on the host or linked template level</p> |`.+` |
|{$VFS.DEV.DEVNAME.NOT_MATCHES} |<p>This macro is used in block devices discovery. Can be overridden on the host or linked template level</p> |`^(loop[0-9]*|sd[a-z][0-9]+|nbd[0-9]+|sr[0-9]+|fd[0-9]+|dm-[0-9]+|ram[0-9]+|ploop[a-z0-9]+|md[0-9]*|hcp[0-9]*|zram[0-9]*)` |
|{$VFS.FS.FREE.MIN.CRIT} |<p>The critical threshold of the filesystem utilization.</p> |`5G` |
|{$VFS.FS.FREE.MIN.WARN} |<p>The warning threshold of the filesystem utilization.</p> |`10G` |
|{$VFS.FS.FSNAME.MATCHES} |<p>This macro is used in filesystems discovery. Can be overridden on the host or linked template level</p> |`.+` |
|{$VFS.FS.FSNAME.NOT_MATCHES} |<p>This macro is used in filesystems discovery. Can be overridden on the host or linked template level</p> |`^(/dev|/sys|/run|/proc|.+/shm$)` |
|{$VFS.FS.FSTYPE.MATCHES} |<p>This macro is used in filesystems discovery. Can be overridden on the host or linked template level</p> |`.*(\.4|\.9|hrStorageFixedDisk|hrStorageFlashMemory)$` |
|{$VFS.FS.FSTYPE.NOT_MATCHES} |<p>This macro is used in filesystems discovery. Can be overridden on the host or linked template level</p> |`^\s$` |
|{$VFS.FS.INODE.PFREE.MIN.CRIT} |<p>-</p> |`10` |
|{$VFS.FS.INODE.PFREE.MIN.WARN} |<p>-</p> |`20` |
|{$VFS.FS.PUSED.MAX.CRIT} |<p>-</p> |`90` |
|{$VFS.FS.PUSED.MAX.WARN} |<p>-</p> |`80` |

## Template links

There are no template links in this template.

## Discovery rules

|Name|Description|Type|Key and additional info|
|----|-----------|----|----|
|Block devices discovery |<p>Block devices are discovered from UCD-DISKIO-MIB::diskIOTable (http://net-snmp.sourceforge.net/docs/mibs/ucdDiskIOMIB.html#diskIOTable)</p> |SNMP |vfs.dev.discovery[snmp]<p>**Filter**:</p>AND <p>- {#DEVNAME} MATCHES_REGEX `{$VFS.DEV.DEVNAME.MATCHES}`</p><p>- {#DEVNAME} NOT_MATCHES_REGEX `{$VFS.DEV.DEVNAME.NOT_MATCHES}`</p> |
|CPU discovery |<p>This discovery will create set of per core CPU metrics from UCD-SNMP-MIB, using {#CPU.COUNT} in preprocessing. That's the only reason why LLD is used.</p> |DEPENDENT |cpu.discovery[snmp]<p>**Preprocessing**:</p><p>- JAVASCRIPT: `The text is too long. Please see the template.`</p> |
|EtherLike-MIB Discovery |<p>Discovering interfaces from IF-MIB and EtherLike-MIB. Interfaces with up(1) Operational Status are discovered.</p> |SNMP |net.if.duplex.discovery<p>**Preprocessing**:</p><p>- JAVASCRIPT: `The text is too long. Please see the template.`</p><p>**Filter**:</p>AND <p>- {#IFOPERSTATUS} MATCHES_REGEX `1`</p><p>- {#SNMPVALUE} MATCHES_REGEX `(2|3)`</p> |
|Mounted filesystem discovery |<p>HOST-RESOURCES-MIB::hrStorage discovery with storage filter</p> |SNMP |vfs.fs.discovery[snmp]<p>**Filter**:</p>AND <p>- {#FSTYPE} MATCHES_REGEX `{$VFS.FS.FSTYPE.MATCHES}`</p><p>- {#FSTYPE} NOT_MATCHES_REGEX `{$VFS.FS.FSTYPE.NOT_MATCHES}`</p><p>- {#FSNAME} MATCHES_REGEX `{$VFS.FS.FSNAME.MATCHES}`</p><p>- {#FSNAME} NOT_MATCHES_REGEX `{$VFS.FS.FSNAME.NOT_MATCHES}`</p> |
|Network interfaces discovery |<p>Discovering interfaces from IF-MIB.</p> |SNMP |net.if.discovery<p>**Filter**:</p>AND <p>- {#IFADMINSTATUS} MATCHES_REGEX `{$NET.IF.IFADMINSTATUS.MATCHES}`</p><p>- {#IFADMINSTATUS} NOT_MATCHES_REGEX `{$NET.IF.IFADMINSTATUS.NOT_MATCHES}`</p><p>- {#IFOPERSTATUS} MATCHES_REGEX `{$NET.IF.IFOPERSTATUS.MATCHES}`</p><p>- {#IFOPERSTATUS} NOT_MATCHES_REGEX `{$NET.IF.IFOPERSTATUS.NOT_MATCHES}`</p><p>- {#IFNAME} MATCHES_REGEX `{$NET.IF.IFNAME.MATCHES}`</p><p>- {#IFNAME} NOT_MATCHES_REGEX `{$NET.IF.IFNAME.NOT_MATCHES}`</p><p>- {#IFDESCR} MATCHES_REGEX `{$NET.IF.IFDESCR.MATCHES}`</p><p>- {#IFDESCR} NOT_MATCHES_REGEX `{$NET.IF.IFDESCR.NOT_MATCHES}`</p><p>- {#IFALIAS} MATCHES_REGEX `{$NET.IF.IFALIAS.MATCHES}`</p><p>- {#IFALIAS} NOT_MATCHES_REGEX `{$NET.IF.IFALIAS.NOT_MATCHES}`</p><p>- {#IFTYPE} MATCHES_REGEX `{$NET.IF.IFTYPE.MATCHES}`</p><p>- {#IFTYPE} NOT_MATCHES_REGEX `{$NET.IF.IFTYPE.NOT_MATCHES}`</p> |

## Items collected

|Group|Name|Description|Type|Key and additional info|
|-----|----|-----------|----|---------------------|
|CPU |Load average (1m avg) |<p>MIB: UCD-SNMP-MIB</p> |SNMP |system.cpu.load.avg1[laLoad.1] |
|CPU |Load average (5m avg) |<p>MIB: UCD-SNMP-MIB</p> |SNMP |system.cpu.load.avg5[laLoad.2] |
|CPU |Load average (15m avg) |<p>MIB: UCD-SNMP-MIB</p> |SNMP |system.cpu.load.avg15[laLoad.3] |
|CPU |Number of CPUs |<p>MIB: HOST-RESOURCES-MIB</p><p>Count the number of CPU cores by counting number of cores discovered in hrProcessorTable using LLD</p> |SNMP |system.cpu.num[snmp]<p>**Preprocessing**:</p><p>- JAVASCRIPT: `//count the number of cores return JSON.parse(value).length; `</p> |
|CPU |Interrupts per second |<p>-</p> |SNMP |system.cpu.intr[ssRawInterrupts.0]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p> |
|CPU |Context switches per second |<p>-</p> |SNMP |system.cpu.switches[ssRawContexts.0]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p> |
|CPU |CPU idle time |<p>MIB: UCD-SNMP-MIB</p><p>The time the CPU has spent doing nothing.</p> |SNMP |system.cpu.idle[ssCpuRawIdle.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU system time |<p>MIB: UCD-SNMP-MIB</p><p>The time the CPU has spent running the kernel and its processes.</p> |SNMP |system.cpu.system[ssCpuRawSystem.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU user time |<p>MIB: UCD-SNMP-MIB</p><p>The time the CPU has spent running users' processes that are not niced.</p> |SNMP |system.cpu.user[ssCpuRawUser.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU steal time |<p>MIB: UCD-SNMP-MIB</p><p>The amount of CPU 'stolen' from this virtual machine by the hypervisor for other tasks (such as running another virtual machine).</p> |SNMP |system.cpu.steal[ssCpuRawSteal.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU softirq time |<p>MIB: UCD-SNMP-MIB</p><p>The amount of time the CPU has been servicing software interrupts.</p> |SNMP |system.cpu.softirq[ssCpuRawSoftIRQ.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU nice time |<p>MIB: UCD-SNMP-MIB</p><p>The time the CPU has spent running users' processes that have been niced.</p> |SNMP |system.cpu.nice[ssCpuRawNice.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU iowait time |<p>MIB: UCD-SNMP-MIB</p><p>Amount of time the CPU has been waiting for I/O to complete.</p> |SNMP |system.cpu.iowait[ssCpuRawWait.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU interrupt time |<p>MIB: UCD-SNMP-MIB</p><p>The amount of time the CPU has been servicing hardware interrupts.</p> |SNMP |system.cpu.interrupt[ssCpuRawInterrupt.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU guest time |<p>MIB: UCD-SNMP-MIB</p><p>Guest  time (time  spent  running  a  virtual  CPU  for  a  guest  operating  system).</p> |SNMP |system.cpu.guest[ssCpuRawGuest.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU guest nice time |<p>MIB: UCD-SNMP-MIB</p><p>Time spent running a niced guest (virtual CPU for guest operating systems under the control of the Linux kernel).</p> |SNMP |system.cpu.guest_nice[ssCpuRawGuestNice.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- JAVASCRIPT: `//to get utilization in %, divide by N, where N is number of cores. return value/{#CPU.COUNT} `</p> |
|CPU |CPU utilization |<p>CPU utilization in %.</p> |DEPENDENT |system.cpu.util[snmp,{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- JAVASCRIPT: `//Calculate utilization return (100 - value) `</p> |
|General |SNMP traps (fallback) |<p>The item is used to collect all SNMP traps unmatched by other snmptrap items</p> |SNMP_TRAP |snmptrap.fallback |
|General |System location |<p>MIB: SNMPv2-MIB</p><p>The physical location of this node (e.g., `telephone closet, 3rd floor').  If the location is unknown, the value is the zero-length string.</p> |SNMP |system.location[sysLocation.0]<p>**Preprocessing**:</p><p>- DISCARD_UNCHANGED_HEARTBEAT: `12h`</p> |
|General |System contact details |<p>MIB: SNMPv2-MIB</p><p>The textual identification of the contact person for this managed node, together with information on how to contact this person.  If no contact information is known, the value is the zero-length string.</p> |SNMP |system.contact[sysContact.0]<p>**Preprocessing**:</p><p>- DISCARD_UNCHANGED_HEARTBEAT: `12h`</p> |
|General |System object ID |<p>MIB: SNMPv2-MIB</p><p>The vendor's authoritative identification of the network management subsystem contained in the entity.  This value is allocated within the SMI enterprises subtree (1.3.6.1.4.1) and provides an easy and unambiguous means for determining`what kind of box' is being managed.  For example, if vendor`Flintstones, Inc.' was assigned the subtree1.3.6.1.4.1.4242, it could assign the identifier 1.3.6.1.4.1.4242.1.1 to its `Fred Router'.</p> |SNMP |system.objectid[sysObjectID.0]<p>**Preprocessing**:</p><p>- DISCARD_UNCHANGED_HEARTBEAT: `12h`</p> |
|General |System name |<p>MIB: SNMPv2-MIB</p><p>An administratively-assigned name for this managed node.By convention, this is the node's fully-qualified domain name.  If the name is unknown, the value is the zero-length string.</p> |SNMP |system.name<p>**Preprocessing**:</p><p>- DISCARD_UNCHANGED_HEARTBEAT: `12h`</p> |
|General |System description |<p>MIB: SNMPv2-MIB</p><p>A textual description of the entity. This value should</p><p>include the full name and version identification of the system's hardware type, software operating-system, and</p><p>networking software.</p> |SNMP |system.descr[sysDescr.0]<p>**Preprocessing**:</p><p>- DISCARD_UNCHANGED_HEARTBEAT: `12h`</p> |
|Memory |Memory utilization |<p>Please note that memory utilization is a rough estimate, since memory available is calculated as free+buffers+cached, which is not 100% accurate, but the best we can get using SNMP.</p> |CALCULATED |vm.memory.util[snmp]<p>**Expression**:</p>`(last(//vm.memory.total[memTotalReal.0])-(last(//vm.memory.free[memAvailReal.0])+last(//vm.memory.buffers[memBuffer.0])+last(//vm.memory.cached[memCached.0])))/last(//vm.memory.total[memTotalReal.0])*100` |
|Memory |Free memory |<p>MIB: UCD-SNMP-MIB</p> |SNMP |vm.memory.free[memAvailReal.0]<p>**Preprocessing**:</p><p>- MULTIPLIER: `1024`</p> |
|Memory |Memory (buffers) |<p>MIB: UCD-SNMP-MIB</p><p>Memory used by kernel buffers (Buffers in /proc/meminfo).</p> |SNMP |vm.memory.buffers[memBuffer.0]<p>**Preprocessing**:</p><p>- MULTIPLIER: `1024`</p> |
|Memory |Memory (cached) |<p>MIB: UCD-SNMP-MIB</p><p>Memory used by the page cache and slabs (Cached and Slab in /proc/meminfo).</p> |SNMP |vm.memory.cached[memCached.0]<p>**Preprocessing**:</p><p>- MULTIPLIER: `1024`</p> |
|Memory |Total memory |<p>MIB: UCD-SNMP-MIB</p><p>Total memory in Bytes.</p> |SNMP |vm.memory.total[memTotalReal.0]<p>**Preprocessing**:</p><p>- MULTIPLIER: `1024`</p> |
|Memory |Available memory |<p>Please note that memory utilization is a rough estimate, since memory available is calculated as free+buffers+cached, which is not 100% accurate, but the best we can get using SNMP.</p> |CALCULATED |vm.memory.available[snmp]<p>**Expression**:</p>`last(//vm.memory.free[memAvailReal.0])+last(//vm.memory.buffers[memBuffer.0])+last(//vm.memory.cached[memCached.0])` |
|Memory |Total swap space |<p>MIB: UCD-SNMP-MIB</p><p>The total amount of swap space configured for this host.</p> |SNMP |system.swap.total[memTotalSwap.0]<p>**Preprocessing**:</p><p>- MULTIPLIER: `1024`</p> |
|Memory |Free swap space |<p>MIB: UCD-SNMP-MIB</p><p>The amount of swap space currently unused or available.</p> |SNMP |system.swap.free[memAvailSwap.0]<p>**Preprocessing**:</p><p>- MULTIPLIER: `1024`</p> |
|Memory |Free swap space in % |<p>The free space of swap volume/file in percent.</p> |CALCULATED |system.swap.pfree[snmp]<p>**Expression**:</p>`last(//system.swap.free[memAvailSwap.0])/last(//system.swap.total[memTotalSwap.0])*100` |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Duplex status |<p>MIB: EtherLike-MIB</p><p>The current mode of operation of the MAC</p><p>entity.  'unknown' indicates that the current</p><p>duplex mode could not be determined.</p><p>Management control of the duplex mode is</p><p>accomplished through the MAU MIB.  When</p><p>an interface does not support autonegotiation,</p><p>or when autonegotiation is not enabled, the</p><p>duplex mode is controlled using</p><p>ifMauDefaultType.  When autonegotiation is</p><p>supported and enabled, duplex mode is controlled</p><p>using ifMauAutoNegAdvertisedBits.  In either</p><p>case, the currently operating duplex mode is</p><p>reflected both in this object and in ifMauType.</p><p>Note that this object provides redundant</p><p>information with ifMauType.  Normally, redundant</p><p>objects are discouraged.  However, in this</p><p>instance, it allows a management application to</p><p>determine the duplex status of an interface</p><p>without having to know every possible value of</p><p>ifMauType.  This was felt to be sufficiently</p><p>valuable to justify the redundancy.</p><p>Reference: [IEEE 802.3 Std.], 30.3.1.1.32,aDuplexStatus.</p> |SNMP |net.if.duplex[dot3StatsDuplexStatus.{#SNMPINDEX}] |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Operational status |<p>MIB: IF-MIB</p><p>The current operational state of the interface.</p><p>- The testing(3) state indicates that no operational packet scan be passed</p><p>- If ifAdminStatus is down(2) then ifOperStatus should be down(2)</p><p>- If ifAdminStatus is changed to up(1) then ifOperStatus should change to up(1) if the interface is ready to transmit and receive network traffic</p><p>- It should change todormant(5) if the interface is waiting for external actions (such as a serial line waiting for an incoming connection)</p><p>- It should remain in the down(2) state if and only if there is a fault that prevents it from going to the up(1) state</p><p>- It should remain in the notPresent(6) state if the interface has missing(typically, hardware) components.</p> |SNMP |net.if.status[ifOperStatus.{#SNMPINDEX}] |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Bits received |<p>MIB: IF-MIB</p><p>The total number of octets received on the interface, including framing characters. This object is a 64-bit version of ifInOctets. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.</p> |SNMP |net.if.in[ifHCInOctets.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- MULTIPLIER: `8`</p> |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Bits sent |<p>MIB: IF-MIB</p><p>The total number of octets transmitted out of the interface, including framing characters. This object is a 64-bit version of ifOutOctets.Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.</p> |SNMP |net.if.out[ifHCOutOctets.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p><p>- MULTIPLIER: `8`</p> |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Inbound packets with errors |<p>MIB: IF-MIB</p><p>For packet-oriented interfaces, the number of inbound packets that contained errors preventing them from being deliverable to a higher-layer protocol.  For character-oriented or fixed-length interfaces, the number of inbound transmission units that contained errors preventing them from being deliverable to a higher-layer protocol. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.</p> |SNMP |net.if.in.errors[ifInErrors.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p> |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Outbound packets with errors |<p>MIB: IF-MIB</p><p>For packet-oriented interfaces, the number of outbound packets that contained errors preventing them from being deliverable to a higher-layer protocol.  For character-oriented or fixed-length interfaces, the number of outbound transmission units that contained errors preventing them from being deliverable to a higher-layer protocol. Discontinuities in the value of this counter can occur at re-initialization of the management system, and at other times as indicated by the value of ifCounterDiscontinuityTime.</p> |SNMP |net.if.out.errors[ifOutErrors.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p> |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Outbound packets discarded |<p>MIB: IF-MIB</p><p>The number of outbound packets which were chosen to be discarded</p><p>even though no errors had been detected to prevent their being deliverable to a higher-layer protocol.</p><p>One possible reason for discarding such a packet could be to free up buffer space.</p><p>Discontinuities in the value of this counter can occur at re-initialization of the management system,</p><p>and at other times as indicated by the value of ifCounterDiscontinuityTime.</p> |SNMP |net.if.out.discards[ifOutDiscards.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p> |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Inbound packets discarded |<p>MIB: IF-MIB</p><p>The number of inbound packets which were chosen to be discarded</p><p>even though no errors had been detected to prevent their being deliverable to a higher-layer protocol.</p><p>One possible reason for discarding such a packet could be to free up buffer space.</p><p>Discontinuities in the value of this counter can occur at re-initialization of the management system,</p><p>and at other times as indicated by the value of ifCounterDiscontinuityTime.</p> |SNMP |net.if.in.discards[ifInDiscards.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p> |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Interface type |<p>MIB: IF-MIB</p><p>The type of interface.</p><p>Additional values for ifType are assigned by the Internet Assigned Numbers Authority (IANA),</p><p>through updating the syntax of the IANAifType textual convention.</p> |SNMP |net.if.type[ifType.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- DISCARD_UNCHANGED_HEARTBEAT: `1d`</p> |
|Network interfaces |Interface {#IFNAME}({#IFALIAS}): Speed |<p>MIB: IF-MIB</p><p>An estimate of the interface's current bandwidth in units of 1,000,000 bits per second. If this object reports a value of `n' then the speed of the interface is somewhere in the range of `n-500,000' to`n+499,999'.  For interfaces which do not vary in bandwidth or for those where no accurate estimation can be made, this object should contain the nominal bandwidth. For a sub-layer which has no concept of bandwidth, this object should be zero.</p> |SNMP |net.if.speed[ifHighSpeed.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- MULTIPLIER: `1000000`</p><p>- DISCARD_UNCHANGED_HEARTBEAT: `1h`</p> |
|Status |Uptime (network) |<p>MIB: SNMPv2-MIB</p><p>The time (in hundredths of a second) since the network management portion of the system was last re-initialized.</p> |SNMP |system.net.uptime[sysUpTime.0]<p>**Preprocessing**:</p><p>- MULTIPLIER: `0.01`</p> |
|Status |Uptime (hardware) |<p>MIB: HOST-RESOURCES-MIB</p><p>The amount of time since this host was last initialized. Note that this is different from sysUpTime in the SNMPv2-MIB [RFC1907] because sysUpTime is the uptime of the network management portion of the system.</p> |SNMP |system.hw.uptime[hrSystemUptime.0]<p>**Preprocessing**:</p><p>- CHECK_NOT_SUPPORTED</p><p>⛔️ON_FAIL: `CUSTOM_VALUE -> 0`</p><p>- MULTIPLIER: `0.01`</p> |
|Status |SNMP agent availability |<p>Availability of SNMP checks on the host. The value of this item corresponds to availability icons in the host list.</p><p>Possible value:</p><p>0 - not available</p><p>1 - available</p><p>2 - unknown</p> |INTERNAL |zabbix[host,snmp,available] |
|Status |ICMP ping |<p>-</p> |SIMPLE |icmpping |
|Status |ICMP loss |<p>-</p> |SIMPLE |icmppingloss |
|Status |ICMP response time |<p>-</p> |SIMPLE |icmppingsec |
|Storage |{#DEVNAME}: Disk read rate |<p>MIB: UCD-DISKIO-MIB</p><p>The number of read accesses from this device since boot.</p> |SNMP |vfs.dev.read.rate[diskIOReads.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p> |
|Storage |{#DEVNAME}: Disk write rate |<p>MIB: UCD-DISKIO-MIB</p><p>The number of write accesses from this device since boot.</p> |SNMP |vfs.dev.write.rate[diskIOWrites.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- CHANGE_PER_SECOND</p> |
|Storage |{#DEVNAME}: Disk utilization |<p>MIB: UCD-DISKIO-MIB</p><p>The 1 minute average load of disk (%)</p> |SNMP |vfs.dev.util[diskIOLA1.{#SNMPINDEX}] |
|Storage |{#FSNAME}: Used space |<p>MIB: HOST-RESOURCES-MIB</p><p>The amount of the storage represented by this entry that is allocated, in units of hrStorageAllocationUnits.</p> |SNMP |vfs.fs.used[hrStorageUsed.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- MULTIPLIER: `{#ALLOC_UNITS}`</p> |
|Storage |{#FSNAME}: Total space |<p>MIB: HOST-RESOURCES-MIB</p><p>The size of the storage represented by this entry, in units of hrStorageAllocationUnits.</p><p>This object is writable to allow remote configuration of the size of the storage area in those cases where such an operation makes sense and is possible on the underlying system.</p><p>For example, the amount of main storage allocated to a buffer pool might be modified or the amount of disk space allocated to virtual storage might be modified.</p> |SNMP |vfs.fs.total[hrStorageSize.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- MULTIPLIER: `{#ALLOC_UNITS}`</p> |
|Storage |{#FSNAME}: Space utilization |<p>Space utilization in % for {#FSNAME}</p> |CALCULATED |vfs.fs.pused[storageUsedPercentage.{#SNMPINDEX}]<p>**Expression**:</p>`(last(//vfs.fs.used[hrStorageUsed.{#SNMPINDEX}])/last(//vfs.fs.total[hrStorageSize.{#SNMPINDEX}]))*100` |
|Storage |{#FSNAME}: Free inodes in % |<p>MIB: UCD-SNMP-MIB</p><p>If having problems collecting this item make sure access to UCD-SNMP-MIB is allowed.</p> |SNMP |vfs.fs.inode.pfree[dskPercentNode.{#SNMPINDEX}]<p>**Preprocessing**:</p><p>- JAVASCRIPT: `return (100-value);`</p> |

## Triggers

|Name|Description|Expression|Severity|Dependencies and additional info|
|----|-----------|----|----|----|
|Load average is too high |<p>Per CPU load average is too high. Your system may be slow to respond.</p> |`min(/Linux by SNMP/system.cpu.load.avg1[laLoad.1],5m)/last(/Linux by SNMP/system.cpu.num[snmp])>{$LOAD_AVG_PER_CPU.MAX.WARN} and last(/Linux by SNMP/system.cpu.load.avg5[laLoad.2])>0 and last(/Linux by SNMP/system.cpu.load.avg15[laLoad.3])>0` |AVERAGE | |
|High CPU utilization |<p>CPU utilization is too high. The system might be slow to respond.</p> |`min(/Linux by SNMP/system.cpu.util[snmp,{#SNMPINDEX}],5m)>{$CPU.UTIL.CRIT}` |WARNING | |
|System name has changed |<p>System name has changed. Ack to close.</p> |`last(/Linux by SNMP/system.name,#1)<>last(/Linux by SNMP/system.name,#2) and length(last(/Linux by SNMP/system.name))>0` |INFO |<p>Manual close: YES</p> |
|High memory utilization |<p>The system is running out of free memory.</p> |`min(/Linux by SNMP/vm.memory.util[snmp],5m)>{$MEMORY.UTIL.MAX}` |AVERAGE |<p>**Depends on**:</p><p>- Lack of available memory</p> |
|Lack of available memory |<p>-</p> |`max(/Linux by SNMP/vm.memory.available[snmp],5m)<{$MEMORY.AVAILABLE.MIN} and last(/Linux by SNMP/vm.memory.total[memTotalReal.0])>0` |AVERAGE | |
|High swap space usage |<p>This trigger is ignored, if there is no swap configured.</p> |`max(/Linux by SNMP/system.swap.pfree[snmp],5m)<{$SWAP.PFREE.MIN.WARN} and last(/Linux by SNMP/system.swap.total[memTotalSwap.0])>0` |WARNING |<p>**Depends on**:</p><p>- High memory utilization</p><p>- Lack of available memory</p> |
|Interface {#IFNAME}({#IFALIAS}): In half-duplex mode |<p>Please check autonegotiation settings and cabling</p> |`last(/Linux by SNMP/net.if.duplex[dot3StatsDuplexStatus.{#SNMPINDEX}])=2` |WARNING |<p>Manual close: YES</p> |
|Interface {#IFNAME}({#IFALIAS}): Link down |<p>This trigger expression works as follows:</p><p>1. Can be triggered if operations status is down.</p><p>2. {$IFCONTROL:"{#IFNAME}"}=1 - user can redefine Context macro to value - 0. That marks this interface as not important. No new trigger will be fired if this interface is down.</p><p>3. {TEMPLATE_NAME:METRIC.diff()}=1) - trigger fires only if operational status was up(1) sometime before. (So, do not fire 'ethernal off' interfaces.)</p><p>WARNING: if closed manually - won't fire again on next poll, because of .diff.</p> |`{$IFCONTROL:"{#IFNAME}"}=1 and last(/Linux by SNMP/net.if.status[ifOperStatus.{#SNMPINDEX}])=2 and (last(/Linux by SNMP/net.if.status[ifOperStatus.{#SNMPINDEX}],#1)<>last(/Linux by SNMP/net.if.status[ifOperStatus.{#SNMPINDEX}],#2))`<p>Recovery expression:</p>`last(/Linux by SNMP/net.if.status[ifOperStatus.{#SNMPINDEX}])<>2 or {$IFCONTROL:"{#IFNAME}"}=0` |AVERAGE |<p>Manual close: YES</p> |
|Interface {#IFNAME}({#IFALIAS}): High bandwidth usage |<p>The network interface utilization is close to its estimated maximum bandwidth.</p> |`(avg(/Linux by SNMP/net.if.in[ifHCInOctets.{#SNMPINDEX}],15m)>({$IF.UTIL.MAX:"{#IFNAME}"}/100)*last(/Linux by SNMP/net.if.speed[ifHighSpeed.{#SNMPINDEX}]) or avg(/Linux by SNMP/net.if.out[ifHCOutOctets.{#SNMPINDEX}],15m)>({$IF.UTIL.MAX:"{#IFNAME}"}/100)*last(/Linux by SNMP/net.if.speed[ifHighSpeed.{#SNMPINDEX}])) and last(/Linux by SNMP/net.if.speed[ifHighSpeed.{#SNMPINDEX}])>0`<p>Recovery expression:</p>`avg(/Linux by SNMP/net.if.in[ifHCInOctets.{#SNMPINDEX}],15m)<(({$IF.UTIL.MAX:"{#IFNAME}"}-3)/100)*last(/Linux by SNMP/net.if.speed[ifHighSpeed.{#SNMPINDEX}]) and avg(/Linux by SNMP/net.if.out[ifHCOutOctets.{#SNMPINDEX}],15m)<(({$IF.UTIL.MAX:"{#IFNAME}"}-3)/100)*last(/Linux by SNMP/net.if.speed[ifHighSpeed.{#SNMPINDEX}])` |WARNING |<p>Manual close: YES</p><p>**Depends on**:</p><p>- Interface {#IFNAME}({#IFALIAS}): Link down</p> |
|Interface {#IFNAME}({#IFALIAS}): High error rate |<p>Recovers when below 80% of {$IF.ERRORS.WARN:"{#IFNAME}"} threshold</p> |`min(/Linux by SNMP/net.if.in.errors[ifInErrors.{#SNMPINDEX}],5m)>{$IF.ERRORS.WARN:"{#IFNAME}"} or min(/Linux by SNMP/net.if.out.errors[ifOutErrors.{#SNMPINDEX}],5m)>{$IF.ERRORS.WARN:"{#IFNAME}"}`<p>Recovery expression:</p>`max(/Linux by SNMP/net.if.in.errors[ifInErrors.{#SNMPINDEX}],5m)<{$IF.ERRORS.WARN:"{#IFNAME}"}*0.8 and max(/Linux by SNMP/net.if.out.errors[ifOutErrors.{#SNMPINDEX}],5m)<{$IF.ERRORS.WARN:"{#IFNAME}"}*0.8` |WARNING |<p>Manual close: YES</p><p>**Depends on**:</p><p>- Interface {#IFNAME}({#IFALIAS}): Link down</p> |
|Interface {#IFNAME}({#IFALIAS}): Ethernet has changed to lower speed than it was before |<p>This Ethernet connection has transitioned down from its known maximum speed. This might be a sign of autonegotiation issues. Ack to close.</p> |`change(/Linux by SNMP/net.if.speed[ifHighSpeed.{#SNMPINDEX}])<0 and last(/Linux by SNMP/net.if.speed[ifHighSpeed.{#SNMPINDEX}])>0 and ( last(/Linux by SNMP/net.if.type[ifType.{#SNMPINDEX}])=6 or last(/Linux by SNMP/net.if.type[ifType.{#SNMPINDEX}])=7 or last(/Linux by SNMP/net.if.type[ifType.{#SNMPINDEX}])=11 or last(/Linux by SNMP/net.if.type[ifType.{#SNMPINDEX}])=62 or last(/Linux by SNMP/net.if.type[ifType.{#SNMPINDEX}])=69 or last(/Linux by SNMP/net.if.type[ifType.{#SNMPINDEX}])=117 ) and (last(/Linux by SNMP/net.if.status[ifOperStatus.{#SNMPINDEX}])<>2)`<p>Recovery expression:</p>`(change(/Linux by SNMP/net.if.speed[ifHighSpeed.{#SNMPINDEX}])>0 and last(/Linux by SNMP/net.if.speed[ifHighSpeed.{#SNMPINDEX}],#2)>0) or (last(/Linux by SNMP/net.if.status[ifOperStatus.{#SNMPINDEX}])=2)` |INFO |<p>Manual close: YES</p><p>**Depends on**:</p><p>- Interface {#IFNAME}({#IFALIAS}): Link down</p> |
|Host has been restarted |<p>Uptime is less than 10 minutes.</p> |`(last(/Linux by SNMP/system.hw.uptime[hrSystemUptime.0])>0 and last(/Linux by SNMP/system.hw.uptime[hrSystemUptime.0])<10m) or (last(/Linux by SNMP/system.hw.uptime[hrSystemUptime.0])=0 and last(/Linux by SNMP/system.net.uptime[sysUpTime.0])<10m)` |WARNING |<p>Manual close: YES</p><p>**Depends on**:</p><p>- No SNMP data collection</p> |
|No SNMP data collection |<p>SNMP is not available for polling. Please check device connectivity and SNMP settings.</p> |`max(/Linux by SNMP/zabbix[host,snmp,available],{$SNMP.TIMEOUT})=0` |WARNING |<p>**Depends on**:</p><p>- Unavailable by ICMP ping</p> |
|Unavailable by ICMP ping |<p>Last three attempts returned timeout.  Please check device connectivity.</p> |`max(/Linux by SNMP/icmpping,#3)=0` |HIGH | |
|High ICMP ping loss |<p>-</p> |`min(/Linux by SNMP/icmppingloss,5m)>{$ICMP_LOSS_WARN} and min(/Linux by SNMP/icmppingloss,5m)<100` |WARNING |<p>**Depends on**:</p><p>- Unavailable by ICMP ping</p> |
|High ICMP ping response time |<p>-</p> |`avg(/Linux by SNMP/icmppingsec,5m)>{$ICMP_RESPONSE_TIME_WARN}` |WARNING |<p>**Depends on**:</p><p>- High ICMP ping loss</p><p>- Unavailable by ICMP ping</p> |
|{#FSNAME}: Disk space is critically low |<p>Two conditions should match: First, space utilization should be above {$VFS.FS.PUSED.MAX.CRIT:"{#FSNAME}"}.</p><p> Second condition should be one of the following:</p><p> - The disk free space is less than {$VFS.FS.FREE.MIN.CRIT:"{#FSNAME}"}.</p><p> - The disk will be full in less than 24 hours.</p> |`last(/Linux by SNMP/vfs.fs.pused[storageUsedPercentage.{#SNMPINDEX}])>{$VFS.FS.PUSED.MAX.CRIT:"{#FSNAME}"} and ((last(/Linux by SNMP/vfs.fs.total[hrStorageSize.{#SNMPINDEX}])-last(/Linux by SNMP/vfs.fs.used[hrStorageUsed.{#SNMPINDEX}]))<{$VFS.FS.FREE.MIN.CRIT:"{#FSNAME}"} or timeleft(/Linux by SNMP/vfs.fs.pused[storageUsedPercentage.{#SNMPINDEX}],1h,100)<1d) ` |AVERAGE |<p>Manual close: YES</p> |
|{#FSNAME}: Disk space is low |<p>Two conditions should match: First, space utilization should be above {$VFS.FS.PUSED.MAX.WARN:"{#FSNAME}"}.</p><p> Second condition should be one of the following:</p><p> - The disk free space is less than {$VFS.FS.FREE.MIN.WARN:"{#FSNAME}"}.</p><p> - The disk will be full in less than 24 hours.</p> |`last(/Linux by SNMP/vfs.fs.pused[storageUsedPercentage.{#SNMPINDEX}])>{$VFS.FS.PUSED.MAX.WARN:"{#FSNAME}"} and ((last(/Linux by SNMP/vfs.fs.total[hrStorageSize.{#SNMPINDEX}])-last(/Linux by SNMP/vfs.fs.used[hrStorageUsed.{#SNMPINDEX}]))<{$VFS.FS.FREE.MIN.WARN:"{#FSNAME}"} or timeleft(/Linux by SNMP/vfs.fs.pused[storageUsedPercentage.{#SNMPINDEX}],1h,100)<1d) ` |WARNING |<p>Manual close: YES</p><p>**Depends on**:</p><p>- {#FSNAME}: Disk space is critically low</p> |
|{#FSNAME}: Running out of free inodes |<p>It may become impossible to write to disk if there are no index nodes left.</p><p>As symptoms, 'No space left on device' or 'Disk is full' errors may be seen even though free space is available.</p> |`min(/Linux by SNMP/vfs.fs.inode.pfree[dskPercentNode.{#SNMPINDEX}],5m)<{$VFS.FS.INODE.PFREE.MIN.CRIT:"{#FSNAME}"}` |AVERAGE | |
|{#FSNAME}: Running out of free inodes |<p>It may become impossible to write to disk if there are no index nodes left.</p><p>As symptoms, 'No space left on device' or 'Disk is full' errors may be seen even though free space is available.</p> |`min(/Linux by SNMP/vfs.fs.inode.pfree[dskPercentNode.{#SNMPINDEX}],5m)<{$VFS.FS.INODE.PFREE.MIN.WARN:"{#FSNAME}"}` |WARNING |<p>**Depends on**:</p><p>- {#FSNAME}: Running out of free inodes</p> |

## Feedback

Please report any issues with the template at https://support.zabbix.com.

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## References

https://docs.fedoraproject.org/en-US/Fedora/26/html/System_Administrators_Guide/sect-System_Monitoring_Tools-Net-SNMP-Retrieving.html
