Cisco Systems UBR900 UBR924# show controllers cable-modem 0 mac resets, CMACLOGRESETT4EXPIRED

show controllers cable-modem mac

This output indicates that the Cisco uBR900 series acquired a downstream lock, successfully read a UCD, and successfully read a MAP. However, it was unable to communicate with the CMTS after ranging through all upstream transmit power levels. The Cisco uBR900 series tried to communicate with the CMTS 16 times without success, after which it reset the cable interface to try to find a better downstream frequency.

If the DHCP server could not be reached, the error would look like this in the MAC error display:

uBR924# show controllers cable-modem 0 mac errors 497989.804 D01.0 Discover sent no Offer received. 498024.046 D01.0 Discover sent no Offer received. 498058.284 D01.0 Discover sent no Offer received.

No available DHCP Server. No available DHCP Server. No available DHCP Server.

Example 3

The show controllers cable-modem 0 mac resets command shows only the entries in the MAC log that begin with the field CMAC_LOG_RESET. Collectively presenting these fields provides you with a summary of the most recent reasons why the cable interface was reset.

Reset messages and brief explanations are included in the following examples and in Table 10; however, the reset messages in Table 10 do not commonly occur.

In the following example, the configuration file downloaded from the TFTP server could not be read. The file might not exist, or the file might have incorrect permissions.

uBR924# show controllers cable-modem 0 mac resets

62526.114	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
62564.368	CMAC_LOG_RESET_T4_EXPIRED
62677.178	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
62717.462	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
62757.746	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
62796.000	CMAC_LOG_RESET_T4_EXPIRED
62908.808	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
62949.092	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
62989.380	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
63029.662	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
63069.944	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
63110.228	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED
63148.484	CMAC_LOG_RESET_T4_EXPIRED
63261.296	CMAC_LOG_RESET_CONFIG_FILE_READ_FAILED

The following example shows that the DHCP server could not be reached, or that it took too long to respond.

uBR924# show controllers cable-modem 0 mac resets

497989.804 CMAC_LOG_RESET_DHCP_WATCHDOG_EXPIRED 498024.046 CMAC_LOG_RESET_DHCP_WATCHDOG_EXPIRED 498058.284 CMAC_LOG_RESET_DHCP_WATCHDOG_EXPIRED

Configuring the Cisco uBR900 Series Cable Access Routers 91