Re: Multicast Configuration

well i think it is for sure a special case when using the ping test and
multicast from the cli

but from what i see it does just "broadcast" it out all interfaces whether
it is one 'IP IGMP JOIN GROUP' command or none, so this might change with a
fully functional multicast setup, and of course with "real" multicast
streams not using the icmp testing

TEST on single router with no igmp configured and then test with igmp
configured on loopback interface showing "broadcast" results:

R1#sh ip igmp interface
R1#ping 239.0.0.1
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 239.0.0.1, timeout is 2 seconds:
*Mar 1 00:57:26.087: IP: s=150.100.40.4 (local), d=239.0.0.1
(FastEthernet0/0), len 100, sending broad/multicast
*Mar 1 00:57:26.087: ICMP type=8, code=0
*Mar 1 00:57:26.091: IP: s=150.100.24.4 (local), d=239.0.0.1 (Serial0/0),
len 100, sending broad/multicast
*Mar 1 00:57:26.091: ICMP type=8, code=0
*Mar 1 00:57:26.091: IP: s=150.100.24.4 (local), d=239.0.0.1 (Serial0/0),
len 100, encapsulation failed
*Mar 1 00:57:26.095: ICMP type=8, code=0
*Mar 1 00:57:26.095: IP: s=150.100.41.4 (local), d=239.0.0.1
(FastEthernet0/1), len 100, sending broad/multicast
*Mar 1 00:57:26.095: ICMP type=8, code=0
*Mar 1 00:57:26.099: IP: s=200.0.0.4 (local), d=239.0.0.1 (Loopback0), len
100, sending broad/multicast
*Mar 1 00:57:26.099: ICMP type=8, code=0
*Mar 1 00:57:26.103: IP: s=200.0.0.4 (Loopback0), d=239.0.0.1, len 100,
unroutable
*Mar 1 00:57:26.107: ICMP type=8, code=0.
R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#int loop0
R1(config-if)#ip igmp join-group 239.0.0.1
*Mar 1 01:03:37.951: IP: s=200.0.0.4 (local), d=239.0.0.1 (Loopback0), len
28, sending broad/multicast, proto=2
*Mar 1 01:03:37.959: IP: s=200.0.0.4 (Loopback0), d=239.0.0.1, len 28, rcvd
0, proto=2

R1(config-if)#do ping 239.0.0.1
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 239.0.0.1, timeout is 2 seconds:
*Mar 1 01:03:44.567: IP: s=150.100.40.4 (local), d=239.0.0.1
(FastEthernet0/0), len 100, sending broad/multicast
*Mar 1 01:03:44.567: ICMP type=8, code=0
*Mar 1 01:03:44.571: IP: s=150.100.24.4 (local), d=239.0.0.1 (Serial0/0),
len 100, sending broad/multicast
*Mar 1 01:03:44.571: ICMP type=8, code=0
*Mar 1 01:03:44.571: IP: s=150.100.24.4 (local), d=239.0.0.1 (Serial0/0),
len 100, encapsulation failed
*Mar 1 01:03:44.575: ICMP type=8, code=0
*Mar 1 01:03:44.575: IP: s=150.100.41.4 (local), d=239.0.0.1
(FastEthernet0/1), len 100, sending broad/multicast
*Mar 1 01:03:44.575: ICMP type=8, code=0
*Mar 1 01:03:44.579: IP: s=200.0.0.4 (local), d=239.0.0.1 (Loopback0), len
100, sending broad/multicast
*Mar 1 01:03:44.579: ICMP type=8, code=0
*Mar 1 01:03:44.587: IP: s=200.0.0.4 (Loopback0), d=239.0.0.1, len 100,
rcvd 2
*Mar 1 01:03:44.587: ICMP type=8, code=0
*Mar 1 01:03:44.587: IP: tableid=0, s=200.0.0.4 (local), d=200.0.0.4
(Loopback0), routed via RIB
*Mar 1 01:03:44.591: IP: s=200.0.0.4 (local), d=200.0.0.4 (Loopback0), len
100, sending
*Mar 1 01:03:44.591: ICMP type=0, code=0
*Mar 1 01:03:44.591: IP: tableid=0, s=200.0.0.4 (Loopback0), d=200.0.0.4
(Loopback0), routed via RIB
*Mar 1 01:03:44.595: IP: s=200.0.0.4 (Loopback0), d=200.0.0.4 (Loopback0),
len 100, rcvd 3
*Mar 1 01:03:44.595: ICMP type=0, code=0

Reply to request 0 from 200.0.0.4, 28 ms

--
Garry L. Baker
"There is no 'patch' for stupidity." - www.sqlsecurity.com
On Mon, Aug 2, 2010 at 7:01 AM, Garth Bryden <
hacked.the.planet.on.28.8k.dialup_at_gmail.com> wrote:
> Hello Group,
>
> I have encountered some strange behaviour with two of my Routers Multicast
> Configuration.
>
> I was setting up a lab to test out the MSDP scenarios in Routing TCP/IP
> Volume 2, on page 619. My Topology is exactly the same except I added an
> additional router onto Kong with IP Routing disabled to simulate a
> multicast
> client.
>
> I went to test connectivity between Kong and R5 but just as I hit enter I
> remembered I did not enable PIM on that interface and therefore IGMP would
> not be enabled on the interface either.. I was surprised when the ping
> worked! I am not sure why it worked, I'm wondering if it is a GNS3 issue or
> have I missed something.
>
> If you dont have the above book the topology is pretty simply for this part
> of the network
>
> ( Kong ) ---- ( R5 )
>
> The link between the two devices is on the 10.1.1.0/30 subnet.
>
> The configuration is as per the below
>
> KONG
> -----------
> Kong#show run
> Building configuration...
> Current configuration : 1465 bytes
> !
> version 12.4
> service timestamps debug datetime msec
> service timestamps log datetime msec
> no service password-encryption
> !
> hostname Kong
> !
> boot-start-marker
> boot-end-marker
> !
> !
> no aaa new-model
> memory-size iomem 5
> ip cef
> !
> !
> !
> !
> no ip domain lookup
> ip multicast-routing
> multilink bundle-name authenticated
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> archive
>  log config
>  hidekeys
> !
> !
> !
> !
> !
> !
> interface Loopback254
>  ip address 10.254.254.1 255.255.255.255
>  ip pim sparse-mode
> !
> interface FastEthernet0/0
>  ip address 192.168.1.5 255.255.255.252
>  speed 100
>  full-duplex
> !
> interface FastEthernet0/1
>  ip address 192.168.1.9 255.255.255.252
>  speed 100
>  full-duplex
> !
> interface FastEthernet1/0
>  ip address 10.1.1.1 255.255.255.252
>  speed 100
>  full-duplex
> !
> router bgp 300
>  no bgp default ipv4-unicast
>  bgp log-neighbor-changes
>  neighbor 192.168.1.6 remote-as 100
>  neighbor 192.168.1.10 remote-as 100
>  !
>  address-family ipv4
>  neighbor 192.168.1.6 activate
>  no auto-summary
>  no synchronization
>  network 10.1.1.0 mask 255.255.255.252
>  network 10.254.254.1 mask 255.255.255.255
>  exit-address-family
>  !
>  address-family ipv4 multicast
>  neighbor 192.168.1.10 activate
>  no auto-summary
>  no synchronization
>  exit-address-family
> !
> ip forward-protocol nd
> !
> !
> ip http server
> no ip http secure-server
> ip pim rp-address 10.254.254.1
> ip msdp peer 192.168.1.10
> ip msdp cache-rejected-sa 10
> !
> !
> !
> !
> control-plane
> !
> !
> !
> !
> !
> !
> !
> !
> !
> line con 0
> line aux 0
> line vty 0 4
>  login
> !
> !
> end
> Kong#
>
>
> R5
> ------
>
> R5#show run
> Building configuration...
> Current configuration : 778 bytes
> !
> version 12.4
> service timestamps debug datetime msec
> service timestamps log datetime msec
> no service password-encryption
> !
> hostname R5
> !
> boot-start-marker
> boot-end-marker
> !
> !
> no aaa new-model
> memory-size iomem 5
> no ip routing
> no ip cef
> !
> !
> !
> !
> multilink bundle-name authenticated
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> !
> archive
>  log config
>  hidekeys
> !
> !
> !
> !
> !
> !
> interface FastEthernet0/0
>  ip address 10.1.1.2 255.255.255.252
>  no ip route-cache
>  ip igmp join-group 239.0.0.1
>  speed 100
>  full-duplex
> !
> interface FastEthernet0/1
>  no ip address
>  no ip route-cache
>  shutdown
>  duplex auto
>  speed auto
> !
> ip default-gateway 10.1.1.1
> ip forward-protocol nd
> !
> !
> ip http server
> no ip http secure-server
> !
> !
> !
> !
> control-plane
> !
> !
> !
> !
> !
> !
> !
> !
> !
> line con 0
> line aux 0
> line vty 0 4
> !
> !
> end
>
> R5#
> Here is the output from my testing
>
> Kong#show ip mroute
> IP Multicast Routing Table
> Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C -
> Connected,
>       L - Local, P - Pruned, R - RP-bit set, F - Register flag,
>       T - SPT-bit set, J - Join SPT, M - MSDP created entry,
>       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
>       U - URD, I - Received Source Specific Host Report,
>       Z - Multicast Tunnel, z - MDT-data group sender,
>       Y - Joined MDT-data group, y - Sending to MDT-data group
> Outgoing interface flags: H - Hardware switched, A - Assert winner
>  Timers: Uptime/Expires
>  Interface state: Interface, Next-Hop or VCD, State/Mode
> (*, 224.0.1.40), 00:06:25/00:02:05, RP 10.254.254.1, flags: SJCL
>  Incoming interface: Null, RPF nbr 0.0.0.0
>  Outgoing interface list:
>    Loopback254, Forward/Sparse, 00:06:25/00:02:05
> Kong#
>
> Kong#show ip igmp interface fa1/0
> FastEthernet1/0 is up, line protocol is up
>  Internet address is 10.1.1.1/30
> *  IGMP is disabled on interface*
>  Multicast routing is disabled on interface
>  Multicast TTL threshold is 0
>  No multicast groups joined by this system
> Kong#
>
> Kong#ping 239.0.0.1
> Type escape sequence to abort.
> Sending 1, 100-byte ICMP Echos to 239.0.0.1, timeout is 2 seconds:
> *Reply to request 0 from 10.1.1.2, 8 ms*
> Kong#
>
> Kong#show ip mroute
> IP Multicast Routing Table
> Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C -
> Connected,
>       L - Local, P - Pruned, R - RP-bit set, F - Register flag,
>       T - SPT-bit set, J - Join SPT, M - MSDP created entry,
>       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
>       U - URD, I - Received Source Specific Host Report,
>       Z - Multicast Tunnel, z - MDT-data group sender,
>       Y - Joined MDT-data group, y - Sending to MDT-data group
> Outgoing interface flags: H - Hardware switched, A - Assert winner
>  Timers: Uptime/Expires
>  Interface state: Interface, Next-Hop or VCD, State/Mode
> (*, 239.0.0.1), 00:00:05/stopped, RP 10.254.254.1, flags: SP
>  Incoming interface: Null, RPF nbr 0.0.0.0
>  Outgoing interface list: Null
> (10.254.254.1, 239.0.0.1), 00:00:05/00:02:54, flags: PTA
>  Incoming interface: Loopback254, RPF nbr 0.0.0.0
> *  Outgoing interface list: Null*
> (*, 224.0.1.40), 00:06:34/00:01:56, RP 10.254.254.1, flags: SJCL
>  Incoming interface: Null, RPF nbr 0.0.0.0
>  Outgoing interface list:
>    Loopback254, Forward/Sparse, 00:06:34/00:01:56
> Kong#
>
> If I enabled PIM on the interface, I get two replies from 10.1.1.2 ! I'm
> confused, if a router goes to ping a multicast group does it just flood the
> ICMP out all interfaces, no matter whether IGMP is enabled or not?
>
> Cheers,
>
> Garth
>
>
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