Subject: Sending IGMP Reports for known groups on Ethernet1/0

From: Michael Jung <[email-masked]>
Date: Tue, 21 May 1996 18:41:42 -0400

How does IOS calculate its known groups for these type advertisements??

They are not perminate group-joins configurated on the router or
groups that are joined by workstations on local (sub)networks.....

<snip>

May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845803: 4:42:23: DVMRP:
Sending IGMP Reports for known groups on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845804: 4:42:23: DVMRP:
Advertise group 224.2.165.86 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845805: 4:42:23: DVMRP:
Advertise group 224.2.171.94 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845806: 4:42:23: DVMRP:
Advertise group 224.2.172.106 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845807: 4:42:23: DVMRP:
Advertise group 224.2.213.30 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845808: 4:42:23: DVMRP:
Advertise group 224.2.147.65 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845809: 4:42:23: DVMRP:
Advertise group 224.2.202.21 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845810: 4:42:23: DVMRP:
Advertise group 224.2.156.56 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845811: 4:42:23: DVMRP:
Advertise group 224.2.213.97 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845812: 4:42:23: DVMRP:
Advertise group 224.2.163.24 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845813: 4:42:23: DVMRP:
Advertise group 224.2.118.247 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845814: 4:42:23: DVMRP:
Advertise group 224.2.68.197 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845815: 4:42:23: DVMRP:
Advertise group 224.2.253.119 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845816: 4:42:23: DVMRP:
Advertise group 224.2.248.110 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845817: 4:42:23: DVMRP:
Advertise group 224.2.37.184 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845818: 4:42:23: DVMRP:
Advertise group 224.2.154.247 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845819: 4:42:23: DVMRP:
Advertise group 224.2.231.173 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845820: 4:42:23: DVMRP:
Advertise group 224.2.51.120 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845821: 4:42:23: DVMRP:
Advertise group 224.2.209.131 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845822: 4:42:23: DVMRP:
Advertise group 224.1.1.94 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845823: 4:42:23: DVMRP:
Advertise group 224.2.238.203 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845824: 4:42:23: DVMRP:
Advertise group 224.2.129.168 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845825: 4:42:23: DVMRP:
Advertise group 224.2.91.98 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845826: 4:42:23: DVMRP:
Advertise group 224.2.46.23 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845827: 4:42:23: DVMRP:
Advertise group 224.2.209.211 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845828: 4:42:23: DVMRP:
Advertise group 224.2.0.1 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845829: 4:42:23: DVMRP:
Advertise group 233.0.0.1 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845830: 4:42:23: DVMRP:
Advertise group 224.2.176.186 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845831: 4:42:23: DVMRP:
Advertise group 224.2.155.147 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845832: 4:42:23: DVMRP:
Advertise group 224.2.152.145 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845833: 4:42:23: DVMRP:
Advertise group 224.2.228.244 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845834: 4:42:23: DVMRP:
Advertise group 224.2.63.47 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845835: 4:42:23: DVMRP:
Advertise group 224.2.214.192 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845836: 4:42:23: DVMRP:
Advertise group 224.2.206.216 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845837: 4:42:23: DVMRP:
Advertise group 224.0.1.24 on Ethernet1/0
May 16 18:50:24 Ethernet1/0.c7000.finall.com 2845838: 4:42:23: DVMRP:
Building Report for Tunnel1 224.0.0.4

tia --mikej

Michael Jung
Financial Alliance Processing Services, Inc.
[email-masked]

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From: Liming Wei <[email-masked]>
Date: Tue, 21 May 96 16:11:53 PDT

> groups that are joined by workstations on local (sub)networks.....

These IGMP reports are sent by the PIM-DVMRP border router for those
non-negative state mroute entries when you don't enable DVMRP
unicast routing on the cisco.

> Advertise group 224.2.165.86 on Ethernet1/0

Configuring "ip dvmrp unicast-routing" on ethernet1/0 will
disable these IGMP reports (when you decide to run dvmrp unicast
routing on the cisco boxes). As a result, the cisco will poison
revserse the relevant DVMRP routes.

-Liming