snmpset: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/snmpset - from package: net-snmp-utils

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/snmpset - from package: snmp

You may install the required package with command apt-get install {package}

Error in other languages:
snmpset: bevel nie gevind nie
snmpset: comandă negăsită
snmpset: comando não encontrado
snmpset: commande introuvable
snmpset: command not found
snmpset: käsku ei ole
snmpset: không tìm thấy lệnh
snmpset: komanda nerasta
snmpset: Kommando nicht gefunden.
snmpset: kommandot finns inte
snmpset: komut yok
snmpset: nie znaleziono polecenia
snmpset: níor aimsíodh an t-ordú
snmpset: no se encontró la orden
snmpset: no s'ha trobat l'ordre
snmpset: opdracht niet gevonden
snmpset: parancs nem található
snmpset: perintah tidak ditemukan
snmpset: príkaz nenájdený
snmpset: příkaz nenalezen
snmpset: команда не найдена
snmpset: командата не е открита
snmpset: 命令找不到
snmpset: コマンドが見つかりません