Comtech EF Data CDM-570/L Vipersat Parameter Editor - Manual (Page 40)

Network
2-24 CDM-570/L, CDD-56X Parameter Editor User Guide
tionally request to join an IGMP group at an interval specified in the Unsolic-
ited Report Interval dialog box (see below).
Version
Selecting either the V1 or V2 radio button determines which version of the
IGMP protocol will be used when attempting to join a group on a multicast
server via an unsolicited report. When the modem/router is configured to recog-
nize IGMP queries, it will respond to a query in the same version that the server
used to initiate the query.
Router Alert Option for V1 Report
Selecting the Router Alert Option for V1 Report option enables a special-
case ability to use some Cisco routers which require the definition of a router
alert option to recognize a report from a client to join a multicast group. The IP
Router Alert Option is defined in RFC2113 and was introduced by Cisco.
While this option is not part of the IGMP standard, most IGMP V2 implementa-
tions contain this option.
Check whether or not your router requires this option as most implementations
of IGMP V1 do not contain this option. This parameter is defined for those
special cases, in which a Cisco router is configured as an IGMP V1 server, to
prevent possible conflicts in networks.
If the box is selected, the modem/router will generate IGMP reports to join
multicast groups as specifically required by some Cisco router configurations. If
the box is not selected, the unit will generate IGMP reports to join multicast
groups as defined and implemented by most IGMP servers.
Unsolicited Report Interval
The Unsolicited Report Interval dialog box configures the modem/router to
generate unsolicited reports to join a multicast group at specified time intervals.
Each unsolicited report to join a multicast group will use the version of the
IGMP protocol as specified by the IGMP version being used.
The value entered for this parameter specifies the number of seconds between
unsolicited reports. Entering a zero in the dialog box means no unsolicited
reports to join a Multicast group will be generated by the unit.