Filter
Top Products
12-5
Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter 12 CTC Network Connectivity
12.2.3 Scenario 3: Using Proxy ARP to Enable an ONS 15454 SDH Gateway
Scenario 3 is similar to Scenario 1, but only one ONS 15454 SDH (#1) connects to the LAN
(Figure 12-3). Two ONS 15454 SDH nodes (#2 and #3) connect to ONS 15454 SDH #1 through the SDH
DCC. Because all three nodes are on the same subnet, proxy ARP enables ONS 15454 SDH #1 to serve
as a gateway for ONS 15454 SDH #2 and #3.
Note This scenario assumes all CTC connections are to ONS 15454 SDH #1. If you connect a laptop to
ONS 15454 SDH #2 or #3, network partitioning occurs; neither the laptop or the CTC computer can see
all nodes. If you want laptops to connect directly to end network elements, you need to create static
routes (see Scenario 5) or enable the ONS 15454 SDH proxy server (see Scenario 7).
Figure 12-3 Scenario 3: Using Proxy ARP
You can also use proxy ARP to communicate with hosts attached to the craft Ethernet ports of
DCC-connected nodes (Figure 12-4). The node with an attached host must have a static route to the host.
Static routes are propagated to all DCC peers using OSPF. The existing proxy ARP node is the gateway
for additional hosts. Each node examines its routing table for routes to hosts that are not connected to
the DCC network but are within the subnet. The existing proxy server replies to ARP requests for these
additional hosts with the node MAC address. The existence of the host route in the routing table ensures
that the IP packets addressed to the additional hosts are routed properly. Other than establishing a static
route between a node and an additional host, no provisioning is necessary. The following restrictions
apply:
• Only one node acts as the proxy ARP server for any given additional host.
• A node cannot be the proxy ARP server for a host connected to its Ethernet port.
CTC Workstation
IP Address 192.168.1.100
Subnet Mark at CTC Workstation 255.255.255.0
Default Gateway = N/A
ONS 15454 SDH #2
IP Address 192.168.1.20
Subnet Mask 255.255.255.0
Default Router = N/A
Static Routes = N/A
ONS 15454 SDH #1
IP Address 192.168.1.10
Subnet Mask 255.255.255.0
Default Router = N/A
Static Routes = N/A
ONS 15454 SDH #3
IP Address 192.168.1.30
Subnet Mask 255.255.255.0
Default Router = N/A
Static Routes = N/A
LAN A
SDH RING
71297