Scenario 4: Default Gateway On Ctc Computer; Figure 9-3 Scenario 3: Using Proxy Arp - Cisco ONS 15600 Reference Manual

Chapter 9 Management Network Connectivity
Figure 9-3
Subnet Mask 255.255.255.0
ARP matches higher-level IP addresses to the physical addresses of the destination host. It uses a lookup
table (called the ARP cache) to perform the translation. When the address is not found in the ARP cache,
a broadcast is sent out on the network with a special format called the ARP request. If one of the
machines on the network recognizes its own IP address in the request, it sends an ARP reply back to the
requesting host. The reply contains the physical hardware address of the receiving host. The requesting
host stores this address in its ARP cache so that all subsequent datagrams (packets) to this destination
IP address can be translated to a physical address.
Proxy ARP enables one LAN-connected ONS 15600 SDH to respond to the ARP request for
ONS 15600 SDHs that are not connected to the LAN. (ONS 15600 SDH Proxy ARP requires no user
configuration.) For this response to occur, the DCC-connected ONS 15600 SDHs must reside on the
same subnet. When a LAN device sends an ARP request to an ONS 15600 SDH that is not connected to
the LAN, the gateway ONS 15600 SDH returns its MAC address to the LAN device. The LAN device
then sends the datagram for the remote ONS 15600 SDH to the MAC address of the proxy
ONS 15600 SDH. The proxy ONS 15600 SDH uses its routing table to forward the datagram to the
non-LAN ONS 15600 SDH.

9.2.4 Scenario 4: Default Gateway on CTC Computer

Scenario 4 is similar to Scenario 3, but Nodes 2 and 3 reside on different subnets, 192.168.2.0 and
192.168.3.0, respectively
CTC computer to communicate with Nodes 2 and 3, you would enter Node 1 as the default gateway on
the CTC computer.
78-18400-01
Scenario 3: Using Proxy ARP
CTC Workstation
IP Address 192.168.1.100
Subnet Mark at CTC Workstation 255.255.255.0
Default Gateway = N/A
ONS 15600 SDH #2
IP Address 192.168.1.20
Default Router = N/A
Static Routes = N/A
(Figure
9.2.4 Scenario 4: Default Gateway on CTC Computer
ONS 15600 SDH #1
IP Address 192.168.1.10
Subnet Mask 255.255.255.0
Default Router = N/A
Static Routes = N/A
SDH RING
9-4). Node 1 and the CTC computer are on subnet 192.168.1.0. For the
Cisco ONS 15600 SDH Reference Manual, Release 9.0
LAN A
ONS 15600 SDH #3
IP Address 192.168.1.30
Subnet Mask 255.255.255.0
Default Router = N/A
Static Routes = N/A
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