Cisco ONS 15454 DWDM - Figure

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Cisco ONS 15454 DWDM Installation and Operations Guide, R6.0
August 2005
Chapter 22 Management Connectivity Reference
22.2.8 Scenario 8: Dual GNEs on a Subnet
If you implement the proxy server, note that all DCC-connected ONS 15454s on the same Ethernet
segment must have the same gateway setting. Mixed values produce unpredictable results, and might
leave some nodes unreachable through the shared Ethernet segment.
If nodes become unreachable, correct the setting by performing one of the following:
• Disconnect the craft computer from the unreachable ONS 15454. Connect to the ONS 15454
through another network ONS 15454 that has a DCC connection to the unreachable ONS 15454.
• Disconnect all DCCs to the node by disabling them on neighboring nodes. Connect a CTC computer
directly to the ONS 15454 and change its provisioning.
22.2.8 Scenario 8: Dual GNEs on a Subnet
The ONS 15454 provides GNE load balancing, which allows CTC to reach ENEs over multiple GNEs
without the ENEs being advertised over OSPF. This feature allows a network to quickly recover from
the loss of GNE, even if the GNE is on a different subnet. If a GNE fails, all connections through that
GNE fail. CTC disconnects from the failed GNE and from all ENEs for which the GNE was a proxy, and
then reconnects through the remaining GNEs. GNE load balancing reduces the dependency on the launch
GNE and DCC bandwidth, both of which enhance CTC performance.
Note Dual GNEs do not need special provisioning
Figure 22-13 shows a network with dual GNEs on the same subnet.
Table 22-4 Proxy Server Firewall Filtering Rules When Packet Addressed to ONS 15454
Packets Arriving At Rejects
TCC2/TCC2P
Ethernet interface
• UDP (User Datagram Protocol) packets addressed to
the SNMP trap relay port (391)
DCC interface
• TCP (Transmission Control Protocol) packets
addressed to the proxy server port (1080)