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Cisco ONS 15454 Reference Manual, R8.5.x
78-18106-01
Chapter 13 Management Network Conn ectivity
13.2.8 IP Scenario 8: Dual GNEs on a Subnet
If you implement the SOCKS proxy server, note that all DCC-connected ON S 15454s on the same
Ethernet segment must have the same gateway setting. Mixed values produce unpredictable re sults, and
might leave some nodes unreachable through the shared Ethernet segment.
If nodes become unreachable, correct the setting with one of the following actions:
• 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.
13.2.8 IP 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 a 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 depe ndency on the launch
GNE and DCC bandwidth, both of which enhance CTC performance. Figure 13-14 shows a network with
dual GNEs on the same subnet.
Table 13-4 SOCKS Proxy Server Firewall Filtering Rules When Packet Addressed to the
ONS 15454
Packets Arriving At Accepts Rejects
TCC2/TCC2P
Ethernet interface
• All UDP1 packets except those in
the Rejected column
1. UDP = User Datagram Protocol
• UDP packets addressed to the
SNMP trap relay port (391)
DCC interface • All UDP packets
• All TCP2 protocols except
packets addressed to the Telnet
and SOCKS proxy server ports
• OSPF packets
• ICMP3 packets
2. TCP = Transmission Control Protocol
3. ICMP = Internet Control Message Protoco l
• TCP packets addressed to the
Telne t po rt
• TCP packets addressed to the
SOCKS proxy server port
• All packets other than UDP, TCP,
OSPF, ICMP