Installation guide

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Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
OL-2238-03
Chapter 3 Configuring the Cisco Cable Interface
Activating Host-to-Host Communication (Proxy ARP)
Current configuration:
!
interface Cable1/0
ip address 1.1.1.1 255.255.255.0
no keepalive
no cable arp
cable downstream annex B
cable downstream modulation 64qam
cable downstream interleave-depth 32
cable downstream symbol-rate 5056941
cable upstream 0 frequency 15008000
no cable upstream 0 shutdown
Tip If you are having difficulty with verification, make sure you entered the correct port and cable modem
card slot number when you activated ARP and when you entered the
show interface cable command.
Activating Host-to-Host Communication (Proxy ARP)
Cable proxy ARP allows the Cisco uBR7100 series CMTS to issue cable ARP requests on behalf of
cable modems on the same cable network subnet.
Note Because the downstream and upstreams are separate interfaces, modems cannot directly perform ARP
with other modems on the cable plant.
Note The default values for the commands used in this configuration task are adequate in most cases to
configure the Cisco uBR7100 series CMTS.
Activating Cable Proxy ARP Requests
To activate cable proxy ARP for host-to-host communications, use the following command in cable
interface configuration mode.
Verifying Cable Proxy ARP Requests
To verify if cable proxy ARP has been activated or deactivated, enter the more system:running-config
and look for the cable interface configuration information. If cable proxy ARP has been activated, it does
not appear in the output. If cable proxy ARP has been deactivated, it appears in the output as
no cable
proxy-arp
.
CMTS01# more system:running-config
Building configuration...
Table 3-2 Instructions to Activate Cable Proxy ARP Requests
Command Purpose
CMTS01(config-if)# cable proxy-arp
Enable proxy ARP on the cable interface. This is the default.