I have getting this error when i run manualy checkrad

[root@radius mibs]# checkrad cisco 192.168.1.1 766 mlpm264 0000BC3F
SNMP Error:
Received SNMP response with error code
error status: noSuchName
index 1 (OID: 1.3.6.1.4.1.9.2.9.2.1.18.766)
SNMPv1_Session (remote host: "192.168.1.1" [192.168.1.1].161)
                  community: "public"
                 request ID: -422345818
                PDU bufsize: 8000 bytes
                    timeout: 2s
                    retries: 5
                    backoff: 1)
at /usr/local/sbin/checkrad line 221
checkrad: No SNMP answer from cisco.
[root@radius mibs]#

and i got this error when i check log

No SNMP answer from cisco.
user at port S766:
snpwalk: /usr/bin/snmpwalk -r 1 -t 5 -v2c -c 'public' 192.168.1.1 .iso.org.dod.internet.private.enterprises.9.10.19.1.3.1.1.3
Returning 0 (login ok)
Sun Mar 11 15:35:15 2007 checkrad cisco 192.168.1.1 766 mlpm264 0000BC3F
No SNMP answer from cisco.
user at port S766:
snpwalk: /usr/bin/snmpwalk -r 1 -t 5 -v2c -c 'public' 192.168.1.1 .iso.org.dod.internet.private.enterprises.9.10.19.1.3.1.1.3
Returning 0 (login ok)
[root@radius mibs]#

what is this how can i checkrad use with snmp i have enable SNMP on cisco router

$ cat ~/satish/url.txt

System administrator ( Data Center )

please visit this site

http://linux.tulipit.com

Here’s a new way to find what you're looking for - Yahoo! Answers