A modular-cable interface is a narrowband interface associated with one downstream RF channel of the SPA. The same RF channel may be associated with an entirely independent bonding group, and the RF channel could be sharing RF bandwidth with this bonding group.
At the Cisco IOS command line, the interface modular-cable command is used to specify a narrowband channel.
Modular cable interfaces are similar to the downstream portion of cable interfaces and are displayed in the output of commands such as show ip interface, show interfaces, show interface modular-cable, and show running-config.
The following is sample output for the show interface command for a modular-cable interface:
Router# show interfaces
Modular-Cable 1/0/0:1 is up, line protocol is up
Hardware is CMTS MC interface, address is 0011.9221.84be (bia 0011.9221.84be)
MTU 1500 bytes, BW 539 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation MCNS, loopback not set
Keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 1w3d, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
40 packets output, 9968 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
When a SPA is inserted, 24 modular-cable interfaces are created for that SPA. These interfaces are hidden until they are configured and will not be displayed in the output of commands such as show ip interface, show interfaces, show interface modular-cable, and show running-config. See the Hardware Status and Line Protocol Status for a Wideband-Channel and Modular-Cable Interface section for information on the conditions when the line protocol is up for modular-cable interfaces.