Cisco ONS 15454 DWDM - DCN Case Study 1 IP Configuration

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Cisco ONS 15454 DWDM Reference Manual, R8.5
78-18343-02
Chapter 15 Management Network Connectivity
15.3.4 DCN Case Study 1: Ring Topology with Two Subnets and Two DCN Connections
During normal operation, this configuration balances the management traffic load over the two available
DCN connections. If one of the two DCN connections fails, the second DCN connection maintains
accessibility so NE management can continue. However, if complete IP connectivity is required, for
example, for SNMP when SOCKS proxy cannot be used, connection resilience is difficult to achieve
because:
• The ONS 15454 does not support route overloading. Configuring different routers with different
costs for the same network destination is not possible.
• The ONS 15454 always tries to route traffic on the LAN interface when its link is up, and the link
on the NE connected to DCN router is always up.
• If the DCN connection fails, the route is longer available.
One solution is to create a generic routing encapsulation (GRE) tunnel to logically connect the remote
Router 1 and remote Router 2 using the OSC/DCC/GCC network (Figure 15-18). With the GRE tunnel,
both remote routers have an alternate path to reach the NOC network in case of DCN failure. However,
the alternate path might become overloaded on the routing tables, resulting in higher costs.
Figure 15-18 DCN Case Study 1: ONS 15454 Ring with Two Subnets, Two DCN Connections, and
GRE Tunnel
15.3.4.1 DCN Case Study 1 IP Configuration
The following sections show sample IP configuration at the routers and ONS 15454 nodes in DCN Case
Study 1.
15.3.4.1.1 NOC Router Configuration
Interface configuration:
interface Ethernet0/0
ip address 10.58.46.121 255.255.255.192
no ip directed-broadcast
!
interface Ethernet1/0
159496
192.168.100.0/24
192.168.30.0/24
GRE Tunnel
192.168.200.0/24
Router 1 Router 2
.1 .1
.1 .1
.121
.2 .2
.1 .2
192.168.10.0/24
NOC router
NMS
.113
NOC LAN
10.58.46.64/26
192.168.20.0/24