RE: how to properly verify a broadcast to multicast-helper?

Hello Wouter,

Check out volume1 ver5 mcast labs, it is verified using another hit in your ACL combined with broadcast DNS resolution. Turn back on ip domain-lookups and you should see the hits on both sides, the hits on the other broadcast to mcast helper map ACL and the debug mpacket traffic can be used to verify it.

-ryan

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of Wouter Prins
Sent: Monday, May 25, 2009 2:49 PM
To: Cisco certification
Subject: how to properly verify a broadcast to multicast-helper?

hey all,

i was wondering how you can verify a broadcast to multicast helper-map? i
labbed this up and i noticed that i cannot send an ip sla with a udpecho to
the broadcast address (255.255.255.255) as this is disallowed.

So i thought i would send the udpecho to the ip broadcast address of that
subnet: 174.1.26.255 and it is properly send out:

*Mar 1 02:22:52.391: UDP: Random local port generated 49538, network 1
*Mar 1 02:22:52.395: Reserved port 49538 in Transport Port Agent for UDP IP
type 1
*Mar 1 02:22:52.395: UDP: sent src=174.1.26.6(49538),
dst=174.1.26.255(3434), length=24

Now on the router configured for the broadcast to multicast conversion i
configured the following on the interface receiving these udpecho's:

RSRack1R2#
interface FastEthernet0/0
 description "facing ip sla router"
 ip address 174.1.26.2 255.255.255.0
 ip broadcast-address 174.1.26.255
ip pim sparse-mode
 ip multicast helper-map broadcast 226.26.26.26 100
 no ip mroute-cache
end
interface Serial1/0
 description "this interface should have the converted broadcast"
 ip address 174.1.23.2 255.255.255.0
 ip pim sparse-mode
 no ip mroute-cache
 frame-relay map ip 174.1.23.3 203 broadcast
 no frame-relay inverse-arp
end

RSRack1R2#show access-list 100
Extended IP access list 100
    10 permit udp any any eq 3434
RSRack1R2#show run | incl forward
ip forward-protocol nd
ip forward-protocol udp 3434
RSRack1R2#show deb
Generic IP:
  IP multicast packets debugging is on
UDP:
  UDP packet debugging is on
RSRack1R2#
RSRack1R2#show ip pim rp-hash 226.26.26.26
  RP 150.1.1.1 (?), v2v1
    Info source: 150.1.3.3 (?), elected via Auto-RP
         Uptime: 01:35:23, expires: 00:02:53
  PIMv2 Hash Value (mask 0.0.0.0)
    RP 150.1.1.1, via Auto-RP
RSRack1R2#show ip rpf 150.1.1.1
RPF information for ? (150.1.1.1)
  RPF interface: Serial1/0
  RPF neighbor: ? (174.1.23.3)
  RPF route/mask: 150.1.1.0/24
  RPF type: unicast (ospf 1)
  RPF recursion count: 0
  Doing distance-preferred lookups across tables
RSRack1R2#

I dont see any packets being forwarded (RP-mappings are fine and no RPF
failures occuring).

Anyone who has a better idea on verifying this and perhaps why this is not
working? :)

-- 
Wouter Prins
wp_at_null0.nl
0x301FA912
Blogs and organic groups at http://www.ccie.net