From: Petr Lapukhov (petrsoft@gmail.com)
Date: Mon Mar 27 2006 - 10:07:25 GMT-3
Do I get you right:
You point on fact, that even if we specify broadcast address
in "ip multicast-helper map", IOS still uses interface default?
and if we need to change that behavior, we should change
broadcast address on interfacse?
Petr
2006/3/27, Henk de Tombe <henk.de.tombe@qi.nl>:
>
> Hi Group,
>
>
>
> I want to ask you something, I've configured the Multicast helper-map.
> Configs are posted below:
>
>
>
> ROUTER01#sh run
>
> Building configuration...
>
>
>
> Current configuration : 2041 bytes
>
> !
>
> version 12.2
>
> service timestamps debug datetime msec
>
> service timestamps log datetime msec
>
> no service password-encryption
>
> !
>
> hostname ROUTER01
>
> !
>
> logging queue-limit 100
>
> !
>
> memory-size iomem 10
>
> ip subnet-zero
>
> !
>
> !
>
> ip multicast-routing
>
> ip audit notify log
>
> ip audit po max-events 100
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> no voice hpi capture buffer
>
> no voice hpi capture destination
>
> !
>
> !
>
> mta receive maximum-recipients 0
>
> !
>
> !
>
> !
>
> !
>
> interface FastEthernet0/0
>
> ip address 192.168.11.1 255.255.255.0
>
> ip pim dense-mode
>
> ip multicast helper-map broadcast 224.11.11.11 100
>
> duplex auto
>
> speed auto
>
> !
>
> interface Serial0/0
>
> ip address 164.1.0.1 255.255.255.0
>
> ip pim dense-mode
>
> encapsulation frame-relay
>
> ip ospf hello-interval 2
>
> ip ospf dead-interval 4
>
> frame-relay map ip 164.1.0.3 103 broadcast
>
> frame-relay map ip 164.1.0.5 105 broadcast
>
> no frame-relay inverse-arp
>
> frame-relay lmi-type cisco
>
> !
>
> interface FastEthernet0/1
>
> no ip address
>
> shutdown
>
> duplex auto
>
> speed auto
>
> !
>
> interface Serial0/1
>
> no ip address
>
> shutdown
>
> !
>
> router ospf 1
>
> log-adjacency-changes
>
> network 164.1.0.1 0.0.0.0 area 0
>
> network 192.168.11.1 0.0.0.0 area 1
>
> neighbor 164.1.0.3 priority 1
>
> !
>
> ip http server
>
> no ip http secure-server
>
> ip classless
>
> !
>
> !
>
> !
>
> access-list 100 permit udp any any eq domain
>
> access-list 100 deny udp any any
>
> !
>
> call rsvp-sync
>
> !
>
> !
>
> mgcp profile default
>
> !
>
> dial-peer cor custom
>
>
>
>
>
> ROUTER03(config-if)#do sh run
>
> Building configuration...
>
>
>
> Current configuration : 2174 bytes
>
> !
>
> version 12.2
>
> service timestamps debug datetime msec
>
> service timestamps log datetime msec
>
> no service password-encryption
>
> !
>
> hostname ROUTER03
>
> !
>
> logging queue-limit 100
>
> !
>
> ip subnet-zero
>
> !
>
> !
>
> no ip domain lookup
>
> !
>
> ip multicast-routing
>
> ip audit notify log
>
> ip audit po max-events 100
>
> mpls ldp logging neighbor-changes
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> !
>
> no voice hpi capture buffer
>
> no voice hpi capture destination
>
> !
>
> !
>
> mta receive maximum-recipients 0
>
> !
>
> !
>
> !
>
> !
>
> interface FastEthernet0/0
>
> ip address 192.168.33.3 255.255.255.0
>
> ip broadcast-address 192.168.33.255
>
> ip directed-broadcast
>
> duplex auto
>
> speed auto
>
> !
>
> interface FastEthernet0/1
>
> no ip address
>
> shutdown
>
> duplex auto
>
> speed auto
>
> !
>
> interface Serial1/0
>
> ip address 164.1.0.3 255.255.255.0
>
> ip pim dense-mode
>
> ip multicast helper-map 224.11.11.11 192.168.33.255 100
>
> encapsulation frame-relay
>
> ip ospf hello-interval 2
>
> ip ospf dead-interval 4
>
> no ip mroute-cache
>
> serial restart_delay 0
>
> frame-relay map ip 164.1.0.1 301 broadcast
>
> no frame-relay inverse-arp
>
> frame-relay lmi-type cisco
>
> !
>
> interface Serial1/1
>
> no ip address
>
> shutdown
>
> serial restart_delay 0
>
> !
>
> interface Serial1/2
>
> no ip address
>
> shutdown
>
> serial restart_delay 0
>
> !
>
> interface Serial1/3
>
> no ip address
>
> shutdown
>
> serial restart_delay 0
>
> !
>
> router ospf 1
>
> log-adjacency-changes
>
> network 164.1.0.3 0.0.0.0 area 0
>
> network 192.168.33.3 0.0.0.0 area 3
>
> !
>
> ip http server
>
> no ip http secure-server
>
> ip classless
>
> !
>
> !
>
> !
>
> access-list 100 permit udp any any eq domain
>
> access-list 100 deny udp any any
>
>
>
>
>
>
>
>
>
> Please mind that I have no "ip forward protocol udp 53" statement in the
> configuration because this is default configuration.
>
>
>
>
>
> I've tested the above configuration with the following setup:
>
>
>
> switch#host
>
> Translating "host"...domain server (255.255.255.255)
>
> % Unknown command or computer name, or unable to find computer address
>
> switch#sh log | i Vlan
>
> 1d01h: IP: s=192.168.11.8 (local), d=255.255.255.255 (Vlan1), len 50,
> sending broad/multicast
>
> 1d01h: IP: s=192.168.11.8 (local), d=255.255.255.255 (Vlan1), len 50,
> sending full packet
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 50,
> sending broad/multicast
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 50,
> sending full packet
>
> 1d01h: IP: s=192.168.11.8 (Vlan3), d=255.255.255.255, len 50, unroutable
>
>
>
> The switch is attached with VLAN1 to ROUTER1 and with VLAN3 to ROUTER3.
> The
> switch tries to translate "host" and sends a broadcast on all VLANS.
>
>
>
> 1d01h: IP: s=192.168.11.8 (local), d=255.255.255.255 (Vlan1), len 50,
> sending broad/multicast
>
> 1d01h: IP: s=192.168.11.8 (local), d=255.255.255.255 (Vlan1), len 50,
> sending full packet
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 50,
> sending broad/multicast
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 50,
> sending full packet
>
>
>
> After a split second the following entry appears in the debug information:
>
> 1d01h: IP: s=192.168.11.8 (Vlan3), d=255.255.255.255, len 50, unroutable
>
>
>
> IP packets of VLAN1 are "wandering" on VLAN3, this means that ROUTER3 has
> forwarded the broadcast address. To make this absolutely sure, I've
> performed another test:
>
>
>
> Switch# debug ip packet det dump
>
> Switch#GROUPSTUDY <----------------------------
>
> switch#SH LOG | b Vlan3
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 56,
> sending broad/multicast
>
> 1d01h: UDP src=54593, dst=53
>
> 074042D0: 45000038 00000000 E..8....
>
> 074042E0: FF11DA04 C0A82108 FFFFFFFF D5410035 ..Z.@(!.....UA.5
>
> 074042F0: 00240000 005E0100 00010000 00000000 .$...^..........
>
> 07404300: 0A47524F 55505354 55445900 00010001 .GROUPSTUDY.....
> <--------------------------------------------------------------
>
> 07404310:
>
>
>
> I was looking in the log file and saw that the destination ip address is
> 255.255.255.255. I the configuration of ROUTER3 I've configured the
> helper-map to send traffic to address 192.168.33.255, ip multicast
> helper-map 224.11.11.11 192.168.33.255 100.
>
>
>
> I have to change the ip broadcast-address of the egress interface on
> ROUTER3,
>
>
>
> ROUTER03#show ip int fa0/0
>
> FastEthernet0/0 is up, line protocol is up
>
> Internet address is 192.168.33.3/24
>
> Broadcast address is 255.255.255.255
>
>
>
> ROUTER03#conf
>
> *Mar 1 04:31:28.106: %SYS-5-CONFIG_I: Configured from console by console
> t
>
> Enter configuration commands, one per line. End with CNTL/Z.
>
> ROUTER03(config)#int fa0/0
>
> ROUTER03(config-if)#ip broad
>
> ROUTER03(config-if)#ip broadcast-address 192.168.33.255
>
> ROUTER03(config-if)#
>
> ROUTER03(config-if)#do sh ip int fa0/0
>
> FastEthernet0/0 is up, line protocol is up
>
> Internet address is 192.168.33.3/24
>
> Broadcast address is 192.168.33.255
>
>
>
>
>
> switch#clear log
>
> Clear logging buffer [confirm]
>
> switch#end
>
> Translating "end"...domain server (255.255.255.255)
>
> % Unknown command or computer name, or unable to find computer address
>
> switch#sh log | i Vlan3
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 49,
> sending broad/multicast
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 49,
> sending full packet
>
> 1d01h: IP: s=192.168.11.8 (Vlan3), d=192.168.33.255 (Vlan3), len 49, rcvd
> local pkt
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 49,
> sending broad/multicast
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 49,
> sending full packet
>
> 1d01h: IP: s=192.168.11.8 (Vlan3), d=192.168.33.255 (Vlan3), len 49, rcvd
> local pkt
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 49,
> sending broad/multicast
>
> 1d01h: IP: s=192.168.33.8 (local), d=255.255.255.255 (Vlan3), len 49,
> sending full packet
>
> 1d01h: IP: s=192.168.11.8 (Vlan3), d=192.168.33.255 (Vlan3), len 49, rcvd
> local pkt
>
>
>
> The switch now receives broadcasts send to 192.168.33.255.
>
> The ip broadcast-address of the Ethernet interface overrules the
> helper-map
> statement, so if you are asked to send packets to x.x.x.255 you have to
> change the interface broadcast address.
>
> The Doc CD doesn't help us much out,
>
>
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipr
> _c/ipcpt3/1cfmulti.htm#wp1003511
> <
> http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fip
> r_c/ipcpt3/1cfmulti.htm#wp1003511>
>
> For the ones who have IEWB version 2.0, LAB 8 task 7.8 - 7.9 doesn't have
> the ip broadcast address entry as well.
>
>
>
> If I'm totally wrong on this one please let me know,
>
>
>
>
>
> Regards,
>
> Henk
>
> _______________________________________________________________________
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This archive was generated by hypermail 2.1.4 : Sat Apr 01 2006 - 10:07:40 GMT-3