Subject: Help with multicast forwarding over dialup on an AS 5200

From: "Ashok Rao" <[email-masked]>
Date: Tue, 19 Jun 2001 12:21:41 -0400

Any help on this issue is greatly appreciated. Our ability to debug the
problem is limited due to the fact that only the customer has access to
the AS5200. Any suggestions as to what further information should be
elicited from the customer  ?

Summary:
A multicast source is feeding a server (xyz.downlink.skycache.com) running
mrouted. On the other interface of the server, a DVMRP tunnel has been
set up to  an AS 5200 (set up in PIM sparse-dense-mode). The AS 5200 has
dialup connections over multiple T-1 interfaces. Despite RPF checks being
OK on the AS 5200, dial-up receivers cannot receive the data. TTL is set
pretty high on the source.

Network Diagram:

Source ---> MROUTED -----DVMRP Tunnel-- AS 5200 ---- Dial up receiver
	233.40.70.2						serial/T-1

sh ip mroute, sh ip igmp, and sh run (suitably edited for anonymity) is
provided below. Note that serial interfaces have no ip addresses. PIM
sparse-dense is enabled on all interfaces. Note also that sh ip igmp
does not show groups joined - however this output was probably not
captured at the same time  the multicast receiver had dialed in.

>From the as5200.

> sh ip mroute

IP Multicast Routing Table
Flags: D - Dense, S - Sparse, 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 - Advertised via MSDP
Outgoing interface flags: H - Hardware switched
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 233.28.65.255), 01:58:25/00:02:59, RP 0.0.0.0, flags: DJC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Tunnel0, Forward/Dvmrp, 00:02:50/00:00:00
    Ethernet0, Forward/Sparse-Dense, 01:58:25/00:00:00

(63.250.213.6, 233.28.65.255), 00:01:49/00:02:58, flags: CTA
  Incoming interface: Tunnel0, RPF nbr ###.54.169.148, Dvmrp
  Outgoing interface list:
    Ethernet0, Forward/Sparse-Dense, 00:01:49/00:00:00

(*, 233.40.70.2), 01:58:43/00:02:59, RP 0.0.0.0, flags: DJC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Tunnel0, Forward/Dvmrp, 00:03:07/00:00:00
    Ethernet0, Forward/Sparse-Dense, 01:58:43/00:00:00

(63.250.213.6, 233.40.70.2), 00:02:06/00:02:59, flags: CTA
  Incoming interface: Tunnel0, RPF nbr ###.54.169.148, Dvmrp
  Outgoing interface list:
    Ethernet0, Forward/Sparse-Dense, 00:02:06/00:00:00

(*, 233.28.65.45), 01:58:43/00:02:59, RP 0.0.0.0, flags: DJC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Tunnel0, Forward/Dvmrp, 00:03:07/00:00:00
    Ethernet0, Forward/Sparse-Dense, 01:58:43/00:00:00

(63.250.213.147, 233.28.65.45), 00:02:07/00:02:59, flags: CTA
  Incoming interface: Tunnel0, RPF nbr ###.54.169.148, Dvmrp
  Outgoing interface list:
    Ethernet0, Forward/Sparse-Dense, 00:02:07/00:00:00

(*, 224.0.1.40), 4d00h/00:00:00, RP 0.0.0.0, flags: DJCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Tunnel0, Forward/Dvmrp, 00:03:07/00:00:00
    Ethernet0, Forward/Sparse-Dense, 4d00h/00:00:00

(*, 233.28.65.80), 01:58:43/00:02:59, RP 0.0.0.0, flags: DJC
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    Tunnel0, Forward/Dvmrp, 00:03:07/00:00:00
    Ethernet0, Forward/Sparse-Dense, 01:58:43/00:00:00

(63.250.213.5, 233.28.65.80), 00:02:07/00:02:59, flags: CTA
  Incoming interface: Tunnel0, RPF nbr ###.54.169.148, Dvmrp
  Outgoing interface list:
    Ethernet0, Forward/Sparse-Dense, 00:02:07/00:00:00

> sh ip rpf 63.250.213.6

RPF information for ? (63.250.213.6)
  RPF interface: Tunnel0
  RPF neighbor: ###.downlink.skycache.com (###.54.169.148)
  RPF route/mask: 63.250.213.0/24
  RPF type: dvmrp
  RPF recursion count: 1
  Doing distance-preferred lookups across tables

> sh ip igmp group

IGMP Connected Group Membership
Group Address    Interface                Uptime    Expires   Last Reporter
224.0.1.40       Ethernet0                4d00h     never
###.###.###.###

> sh run

:-)

Current configuration : 7151 bytes
!
!
!
!
version 12.1
service nagle
no service pad
service timestamps debug datetime msec localtime show-timezone
service timestamps log datetime msec localtime show-timezone
service password-encryption
service compress-config
!
hostname ...
!
logging buffered 16384 debugging
no logging console
aaa new-model
[ ... some aaa lines deleted ]
spe 1/0 1/7
 firmware location system: ...
spe 2/0 2/7
 firmware location system: ...
!
resource-pool disable
!
ip subnet-zero
no ip finger
ip host ...  ...
ip domain-name ...
ip name-server ...
ip name-server ...
!
no ip bootp server
ip multicast-routing
ip address-pool local
virtual-profile virtual-template 1
virtual-profile aaa
!
sgbp group ....
sgbp member ....  .....
sgbp member ... ...
multilink virtual-template 1
async-bootp gateway ###.###.###.###
async-bootp dns-server ###.###.###.###  ###.###.###.###
isdn switch-type primary-5ess
modemcap entry mica_1:....
modemcap entry micarobust:...
modemcap entry Robust:...
mta receive maximum-recipients 0
!
controller T1 0
 framing esf
 clock source line primary
 linecode b8zs
 pri-group timeslots 1-24

!
controller T1 1
 framing esf
 clock source line secondary 1
 linecode b8zs
 pri-group timeslots 1-24

!
controller T1 2
 framing esf
 linecode b8zs
 pri-group timeslots 1-24

!
controller T1 3
 framing esf
 linecode b8zs
 pri-group timeslots 1-24

!
interface Loopback0
 ip address ###.###.###.### 255.255.255.255
!
interface Loopback1
 ip address ###.###.###.### 255.255.255.255
!
interface Tunnel0
 ip unnumbered Ethernet0
 ip pim sparse-dense-mode
 tunnel source Ethernet0
 tunnel destination xyz.downlink.skycache.com
 tunnel mode dvmrp
!
interface Ethernet0
 ip address ###.###.###.###  255.255.255.0
 ip pim sparse-dense-mode
 ip ospf message-digest-key 1 md5 7 15131B07493824313C362731
!
interface Virtual-Template1
 ip unnumbered Loopback0
 no ip route-cache
 no logging event link-status
 peer default ip address pool default
 ppp authentication pap chap callin
 ppp multilink
!
interface Serial0:23
 no ip address
 ip pim sparse-dense-mode
 encapsulation ppp
 ip mroute-cache
 no keepalive
 dialer rotary-group 1
 dialer-group 1
 isdn switch-type primary-5ess
 isdn incoming-voice modem
 no fair-queue
 no cdp enable
!
interface Serial1:23
 no ip address
 ip pim sparse-dense-mode
 encapsulation ppp
 ip mroute-cache
 no keepalive
 dialer rotary-group 1
 dialer-group 1
 isdn switch-type primary-5ess
 isdn incoming-voice modem
 no fair-queue
 no cdp enable
!
interface Serial2:23
 no ip address
 ip pim sparse-dense-mode
 encapsulation ppp
 ip mroute-cache
 no keepalive
 dialer rotary-group 1
 dialer-group 1
 isdn switch-type primary-5ess
 isdn incoming-voice modem
 no fair-queue
 no cdp enable
!
interface Serial3:23
 no ip address
 ip pim sparse-dense-mode
 encapsulation ppp
 ip mroute-cache
 no keepalive
 dialer rotary-group 1
 dialer-group 1
 isdn switch-type primary-5ess
 isdn incoming-voice modem
 no fair-queue
 no cdp enable
!
interface FastEthernet0
 no ip address
 shutdown
 duplex auto
 speed auto
!
interface Group-Async1
 ip unnumbered Loopback0
 encapsulation ppp
 no ip mroute-cache
 no logging event link-status
 async dynamic address
 async mode interactive
 peer default ip address pool default
 no fair-queue
 no cdp enable
 ppp authentication pap chap callin
 ppp multilink
 group-range 1 96
!
interface Dialer1
 ip unnumbered Loopback0
 encapsulation ppp
 no ip route-cache
 no ip mroute-cache
 no logging event link-status
 no keepalive
 dialer in-band
 dialer idle-timeout 1200
 dialer-group 1
 peer default ip address pool default
 no fair-queue
 no cdp enable
 ppp authentication pap chap callin
 ppp multilink
!
router ospf 100
 log-adjacency-changes
 area 40 authentication message-digest
 area 40 nssa
 area 40 range ###.###.###.### 255.255.255.0
 redistribute connected subnets
 redistribute static subnets
 passive-interface Dialer1
 network ###.###.###.0 0.0.0.255 area 40
!
ip local pool default ###.###.###.###  ###.###.###.###
ip default-gateway ###.###.###.1
ip classless
ip route 0.0.0.0 0.0.0.0 ###.###.###.1
no ip http server
!
ip radius source-interface Ethernet0
logging trap debugging
logging ###.###.###.###
access-list 99 permit ###.###.###.0 0.0.0.255
access-list 125 permit ip ###.###.###.0 0.0.0.255 any
dialer-list 1 protocol ip permit
[ ... some tacacs radius and snmp stuff deleted ... ]
line con 0
 exec-timeout 0 0
 transport input none
line 1 96
 session-timeout 20  output
 modem Dialin
 modem autoconfigure type Robust
 autoselect during-login
 autoselect ppp
line aux 0
line vty 0 1
 access-class 125 in
 exec-timeout 0 0
 transport preferred none