cron 이런메시지가 계속 오네요..

SNMP Error:
no response received
SNMPv1_Session (remote host: "211.54.196.98" [211.54.196.98].161)
                  community: "public"
                 request ID: 1424264214
                PDU bufsize: 8000 bytes
                    timeout: 2s
                    retries: 5
                    backoff: 1)
 at /usr/local/mrtg-2/bin/../lib/mrtg2/SNMP_util.pm line 450
SNMPGET Problem for ifInOctets.2 ifOutOctets.2 sysUptime sysName on public@211.54.196.98:
 at /usr/local/mrtg-2/bin/mrtg line 1491
WARNING: Expected a number but got ''
WARNING: Expected a number but got ''