Subject: Configuring DVMRP between cisco and 3com

From: "Roberto Barnes (SENACYT)" <[email-masked]>
Date: Sat, 13 Jun 1998 16:46:47 -0500 (EST)

We are having problems with our DVMPR configuration between a cisco 2500
running IOS 11.1  and a 3com router.  We have been told the problem is the
cisco configurarion.

Can anyone check the configuration and give us any idea on how to solve
the problem?

Thanks,

Roberto D. Barnes
National Bureau of Science, Technology and Innovation (SENACYT)
Panama, Panama
-----------------
Our topology is as follows: 
1. MBone tunnel provider in the United States to our tunne endpoint, a
cisco 2501 (IOS 11.1).
2. From the cisco 2501, through our Internet's Peering Point cisco 7206
(running BGP4 - IOS 11.1), to our distribution router (the core of our
National MBone) a cisco 7513 (IOS 11.1).

3. The tunnel between the 2501 and the 7513 is using Generic Routing
Encapsulation, and the interface is configured for Frame Relay.

The configurations are as follow:

cisco 2500, IOS 11.1

ip multicast-routing
ip dvmrp route-limit 6000
interface Tunnel0
 description ***2501-7513 Multicast Tunnel***
 ip unnumbered Ethernet0
 ip pim dense-mode
 ip multicast rate-limit in 128
 ip multicast rate-limit out 128
 ip dvmrp unicast-routing
 ip sdr listen
 tunnel source 204.95.131.2
 tunnel destination 168.77.3.193
!
interface Tunnel1
 description ***2501--US MBone provider DVRMP Tunnel***
 ip unnumbered Ethernet0
 ip pim dense-mode
 ip multicast rate-limit in 128
 ip multicast rate-limit out 128
 ip dvmrp unicast-routing
 no ip mroute-cache
 tunnel source 204.95.131.2
 tunnel destination 129.213.128.9
 tunnel mode dvmrp 

----------------------------------------------------------
cisco 7513 IOS 11.1(10.04)

ip multicast-routing
ip dvmrp routehog-notification 6000
ip dvmrp route-limit 6000

interface Tunnel4
 ip unnumbered Serial5/7
 ip pim dense-mode
 ip multicast rate-limit in 128
 ip multicast rate-limit out 128
 ip dvmrp unicast-routing
 ip sdr listen
 tunnel source 168.77.3.193
 tunnel destination 204.95.131.2

interface Serial5/7
 description ***Intel-Senacyt***
 ip address 168.77.3.193 255.255.255.192
 ip pim dense-mode
 bandwidth 64

---

From: Bill Fenner <[email-masked]>
Date: Sun, 14 Jun 1998 13:04:59 PDT

One potential problem is that you are using "ip dvmrp unicast-routing"
on a DVMRP tunnel.  "ip dvmrp unicast-routing" must only be used when
you are running PIM (and only PIM) on that interface.

  Bill