From: AK Singh (singh.anand@gmail.com)
Date: Mon Nov 01 2004 - 07:15:38 GMT-3
Hello John,
Thanks for reply. Actually i went ahead and verified and we don't need
"ip directed-brodcast" on R6's fa0/0 interface. We need "ip pim
dense-mode" configured on that though (which i was missing in my
e-mail below). I believe the reason for that is because R6 is getting
the broadcast anyway ( it would have got routes if rip were configured
etc). We need directed broadcast command only if router needs to send
the brodcast on the subnet.
here is the log. Please do correct if i am missing some vital point.
regards
-Anand
R3:
interface Ethernet2/1
ip address 162.1.38.3 255.255.255.0
ip pim dense-mode
no ip mroute-cache
half-duplex
bridge-group 2
end
R3#sh running-config interface ethernet 2/2
Building configuration...
Current configuration : 182 bytes
!
interface Ethernet2/2
ip address 162.1.3.3 255.255.255.0
ip pim dense-mode
ip multicast helper-map broadcast 224.9.9.9 111
no ip mroute-cache
half-duplex
bridge-group 1
end
R3#sh run
R3#sh running-config | inc i
021094: *Mar 22 02:19:13.288: IP: s=162.1.38.8 (Ethernet2/1),
d=224.0.0.13, len 38, rcvd 0
R3#sh running-config | inc ip
021095: *Mar 22 02:19:15.636: IP: s=162.1.3.1 (Ethernet2/2),
d=224.0.0.13, len 54, rcvd 0
021096: *Mar 22 02:19:15.888: IP: s=192.10.1.254 (Ethernet2/2),
d=224.0.0.9, len 132, unroutable
R3#sh running-config | inc ip fore
021097: *Mar 22 02:19:17.388: IP: s=162.1.3.3 (local), d=224.0.0.13
(Ethernet2/2), len 54, sending broad/multicast
021098: *Mar 22 02:19:17.628: IP: s=162.1.3.1 (Ethernet2/2),
d=255.255.255.255, len 52, rcvd 2
021099: *Mar 22 02:19:17.628: IP(0): s=162.1.3.1 (Ethernet2/2)
d=224.9.9.9 (Ethernet2/1) id=0, prot=17, len=52(52), mforward
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
021100: *Mar 22 02:19:18.056: IP: s=162.1.38.3 (local), d=224.0.0.13
(Ethernet2/1), len 54, sending broad/multicast
R3#sh running-config | inc ip forward
ip forward-protocol udp rip
R3#u all
All possible debugging has been turned off
R3#
R3#sh ip access-lists 111
Extended IP access list 111
10 permit udp any any eq rip (50 matches)
On Sun, 31 Oct 2004 19:00:09 -0500, john matijevic
<matijevi@bellsouth.net> wrote:
> Hello Anand,
> The command is required on R6 fastethernet because its receiving
> broadcasts, and by default the router will drop the directed broadcast,
> so we have to enabled it on that interface, because that is where it
> will receive the directed broadcasts from R1, with R5, it will actually
> receive the multicast traffic, so the command would not be necessary on
> R5, this issue has actually been discussed before with using the
> multicast helper command, if you search the archives you should be able
> to find more information. Make sure you turn on the debugs on R6 and
> R5, so you can see the udp broadcast to 520, and see the rip route on
> R5.
>
> http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/
> fipras_r/1rfipadr.htm#wp1018109
>
> Sincerely,
>
> John Matijevic, CCIE #13254, MCSE, CNE, CCEA
> CEO
> IgorTek Inc.
> 151 Crandon Blvd. #402
> Key Biscayne, FL 33149
> Hablo Espanol
> 305-321-6232
> http://home.bellsouth.net/p/PWP-CCIE
>
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> AK Singh
> Sent: Sunday, October 31, 2004 5:45 PM
> To: Group Study
> Subject: Multicast : CCIE practice LAB3
>
> Hi,
>
> This lab talks about carrying the rip v1 broadcast in a multicast. I
> am drawing a little topology here for others who may not have access
> to the book.
>
> R1
> |
> |
> |Fa0/0
> R6----------------(Vi1)---R5
>
> R5 is supposed to get a RIP v1 update from R1 which is running RipV1.
> R6 and and R5 are running dense-mode multicast. In the solution it
> converts broadcast at R6 into multicast 224.9.9.9 udp and then at R5
> this multicast is converted to broadcast again to subnet of R5's
> virtual-template. I understand this.
>
> The piece which i don't understand is enabling "ip directed-broadcast"
> at R6 fa0/0 interface and R5's virtual-template 1.
>
> What i undestand is that its required only when a router is supposed
> to brroadcast a packet on some segment when it receives a subnetted
> broadcast. Comments please?
>
> Thanks
> -Anand
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Thu Dec 02 2004 - 06:57:37 GMT-3