From: YourPal (dearprudence28@gmail.com)
Date: Sun Feb 24 2008 - 23:02:30 ARST
Hi Group,
Has anyone successfully verified the command "switchport block multicast"?
My understanding is it blocks unknown multicast flooding out to the port. I
set up the following lab scenario:
Physical cabling:
R2 (fa0/0)------(gi0/2) SW2 (gi0/4)------(fa0/0) R4 (fa0/1)------(gi0/4) SW4
(gi0/6)------(fa0/1) R6
Logical:
R2 (fa0/0)--------172.16.24.0/24--------(fa0/0) R4 (fa0/1)--------
172.16.46.0/24--------(fa0/1) R6
Sw2 and SW4 are Cat3560.
SW2's gi0/2 and gi0/4 are in VLAN 24. SW4's gi0/4 and gi0/6 are in VLAN 46.
R2 config
---------
ip multicast-routing
!
interface FastEthernet0/0
ip address 172.16.24.2 255.255.255.0
ip pim dense-mode
ip igmp join-group 239.24.24.24
!
router ospf 1
network 172.16.24.2 0.0.0.0 area 0
!
R4 config
---------
ip multicast-routing
!
interface FastEthernet0/0
ip address 172.16.24.4 255.255.255.0
ip pim dense-mode
!
interface FastEthernet0/1
ip address 172.16.46.4 255.255.255.0
ip pim dense-mode
!
router ospf 1
network 172.16.24.4 0.0.0.0 area 0
network 172.16.46.4 0.0.0.0 area 0
!
R6 config
---------
ip multicast-routing
!
interface FastEthernet0/1
ip address 172.16.46.6 255.255.255.0
ip pim dense-mode
!
router ospf 1
network 172.16.46.6 0.0.0.0 area 0
!
Initially,
SW2#sh ip igmp snooping groups
Vlan Group Type Version Port List
-----------------------------------------------------------------------
24 224.0.1.40 igmp v2 Gi0/2, Gi0/4
24 239.24.24.24 igmp v2 Gi0/2, Gi0/4
R6#pi 239.24.24.24
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 239.24.24.24, timeout is 2 seconds:
Reply to request 0 from 172.16.24.2, 4 ms
Then,
SW2:
no ip igmp snooping vlan 24
!
interface GigabitEthernet0/2
switchport block multicast
!
interface GigabitEthernet0/4
switchport block multicast
!
I'm expecting R6 not able to ping to 239.24.24.24 this time. However it
still can. Can anyone advise whether I'm testing it right at all?
Thank you.
BR,
Emil
This archive was generated by hypermail 2.1.4 : Sat Mar 01 2008 - 16:54:49 ARST