Managed Switch Or Router Modes For Cdm-570L/Al With Optional Ip Module Or Packet Processor - Comtech EF Data CRS-170A Installation And Operation Manual

CRS-170A L-Band 1:1 Redundancy Switch
Introduction
1.3.2.3 Managed Switch or Router Modes for CDM-570L/AL WITH Optional
IP Module or Packet Processor
•
Do not use the M&C Ethernet port (bottom RJ-45 connector) when the optional IP Module
is installed.
•
All configuration changes can only be made to the Online unit and will require you to
" Save Parameters to permanent storage
is also applied to the Backup Modem.
Managed Switch (Ethernet Bridge) Mode: For the CDM-570L/AL in Managed Switch Mode (also known
as "Ethernet Bridge Mode") you MUST use an external Ethernet hub to insure that traffic will continue
after a switchover. If an Ethernet switch is used, there could be a several minute outage while the
Ethernet Switch "re-learns" the correct output Ethernet port. Using a "dumb" Ethernet hub allows LAN-
to-WAN traffic to continue even after a switchover occurs since both modems will be receiving the LAN
traffic.
In Managed Switch Mode, both modems should be assigned a unique Management IP address on the
same subnet in order to share the parameter file.
Router Mode: For the CDM-570L/AL in Router Mode, you should use an external Ethernet switch.
Router mode does not require a "dumb" hub as with Managed Switch Mode and, for performance
reasons, an Ethernet switch is highly recommended.
In Router Mode, both modems must be assigned a unique Management IP address on the same subnet
(172.18.10.21/24 and 172.18.10.22/24 as shown in Figure 1-8 and Figure 1-9). This is used to share the
parameters file. A Traffic IP address on the subnet must also be assigned (172.18.10.20/24) in the Online
unit.
Whichever modem is Online will assume the Traffic IP. When there is a switchover to the backup
modem, this modem will now assume the Traffic IP. As shown in Figure 1-9, the backup modem will also
broadcast a "gratuitous ARP" that will tell all local devices to now associate a new MAC address for the
Traffic IP 172.18.10.20. Each device will update their ARP tables and traffic will resume virtually
instantaneously.
to ensure the configuration change
"
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MN/CRS170A.IOM
Revision 14