Step 4—Interpret the MAC Log File and Take Action
Troubleshooting Tips for the Cisco uBR904 Cable Modem 13
Event 5—Establish IP Connectivity
After ranging is complete, the cable interface on the cable modem is UP. Now the cable modem
accesses a remote DHCP server to get an IP address. The DHCP request also includes the name of
a file that contains additional configuration parameters, the TFTP server’s address and the Time of
Day (TOD) server’s address.
The field
CMAC_LOG_DHCP_ASSIGNED_IP_ADDRESS
indicates the IP address assigned from the DHCP
server to the cable modem interface. The field
CMAC_LOG_DHCP_TFTP_SERVER_ADDRESS
marks the
TFTP server’s address. The field
CMAC_LOG_DHCP_TOD_SERVER_ADDRESS
indicates the time of day
server’s address. The field
CMAC_LOG_DHCP_CONFIG_FILE_NAME
shows the filename containing the
transmission parameters. The field
CMAC_LOG_DHCP_COMPLETE
shows that the IP connectivity was
successful.
508175.968 CMAC_LOG_STATE_CHANGE dhcp_state
508176.982 CMAC_LOG_DHCP_ASSIGNED_IP_ADDRESS 188.188.1.62
508176.984 CMAC_LOG_DHCP_TFTP_SERVER_ADDRESS 4.0.0.1
508176.986 CMAC_LOG_DHCP_TOD_SERVER_ADDRESS 4.0.0.32
508176.988 CMAC_LOG_DHCP_SET_GATEWAY_ADDRESS
508176.988 CMAC_LOG_DHCP_TZ_OFFSET 360
508176.990 CMAC_LOG_DHCP_CONFIG_FILE_NAME platinum.cm
508176.992 CMAC_LOG_DHCP_ERROR_ACQUIRING_SEC_SVR_ADDR
508176.996 CMAC_LOG_DHCP_COMPLETE
Event 6
—
Establish the Time of Day
The Cisco uBR904 cable modem accesses the Time of Day server for the current date and time,
which is used to create time stamps for logged events. The field
CMAC_LOG_TOD_COMPLETE
indicates
a successful time of day sequence.
508177.120 CMAC_LOG_STATE_CHANGE establish_tod_state
508177.126 CMAC_LOG_TOD_REQUEST_SENT
508177.154 CMAC_LOG_TOD_REPLY_RECEIVED 3107617539
508177.158 CMAC_LOG_TOD_COMPLETE
Event 7
—
Establish Security
The cable modem establishes a security association. The
security_association_state
is normally
bypassed since “full security” as defined by the MCNS DOCSIS is not supported.
Note
“Full security” was a request made by MSOs for a very strong authorization and
authentication check by the CMTS. This request has not been granted by cable modem
manufacturers. The Cisco uBR904 fully supports baseline privacy, which protects user’s data from
being “sniffed” on the cable network.
508177.160 CMAC_LOG_STATE_CHANGE security_association_state
508177.162 CMAC_LOG_SECURITY_BYPASSED
