Multicast with PIM-DM
This lab show a multicast routing example using PIM Dense Mode.
Warning
pimdd is broken: Need to Debug it one day
Presentation¶
Network diagram¶
Here is the logical and physical view:
Setting-up the lab¶
Downloading BSD Router Project images¶
Download BSDRP serial image (prevent to have to use an X display) on Sourceforge.
Download Lab scripts¶
More information on these BSDRP lab scripts available on How to build a BSDRP router lab.
Start the lab with 4 routers using emulated e1000 NIC (vtnet interfaces didn’t support multicast-routing on FreeBSD):
tools/BSDRP-lab-bhyve.sh -i /usr/obj/BSDRP.amd64/BSDRP-1.702-full-amd64-serial.img.xz -n 4 -e
BSD Router Project (http://bsdrp.net) - bhyve full-meshed lab script
Setting-up a virtual lab with 4 VM(s):
- Working directory: /tmp/BSDRP
- Each VM have 1 core(s) and 256M RAM
- Emulated NIC: e1000
- Switch mode: bridge + tap
- 0 LAN(s) between all VM
- Full mesh Ethernet links between each VM
VM 1 have the following NIC:
- em0 connected to VM 2
- em1 connected to VM 3
- em2 connected to VM 4
VM 2 have the following NIC:
- em0 connected to VM 1
- em1 connected to VM 3
- em2 connected to VM 4
VM 3 have the following NIC:
- em0 connected to VM 1
- em1 connected to VM 2
- em2 connected to VM 4
VM 4 have the following NIC:
- em0 connected to VM 1
- em1 connected to VM 2
- em2 connected to VM 3
For connecting to VM'serial console, you can use:
- VM 1 : cu -l /dev/nmdm1B
- VM 2 : cu -l /dev/nmdm2B
- VM 3 : cu -l /dev/nmdm3B
- VM 4 : cu -l /dev/nmdm4B
Routers configuration¶
Router 1¶
Configurating, applying changes and saving configuration:
sysrc hostname=VM1 \
gateway_enable=no \
ipv6_gateway_enable=no \
ifconfig_em0="inet 10.0.12.1/24" \
defaultrouter=10.0.12.254
hostname VM1
service netif restart
service routing restart
config save
Router 2¶
sysrc hostname=VM2 \
ifconfig_em0="inet 10.0.12.254/24" \
ifconfig_em1="inet 10.0.23.2/24" \
defaultrouter=10.0.23.3 \
pimdd_enable=yes
cp /usr/local/etc/pimdd.conf.sample /usr/local/etc/pimd.conf
hostname VM2
service netif restart
service routing restart
service pimdd start
config save
Router 3¶
sysrc hostname=VM3 \
ifconfig_em1="inet 10.0.23.3/24" \
ifconfig_em2="inet 10.0.34.254/24" \
defaultrouter=10.0.23.2 \
pimdd_enable=yes
cp /usr/local/etc/pimdd.conf.sample /usr/local/etc/pimd.conf
hostname VM3
service netif restart
service routing restart
service pimdd start
config save
Router 4¶
sysrc hostname=VM4 \
gateway_enable=no \
ipv6_gateway_enable=no \
ifconfig_em2="inet 10.0.34.4/24" \
defaultrouter=10.0.34.254
hostname VM4
service netif restart
service routing restart
config save
Checking pimdd behavior¶
Generating VIF¶
Does the pimdd had correctly generated VIF ?
[root@R2]~# netstat -g
IPv4 Virtual Interface Table
Vif Thresh Local-Address Remote-Address Pkts-In Pkts-Out
0 1 10.0.12.2 0 0
1 1 10.0.23.2 0 0
IPv4 Multicast Forwarding Table is empty
IPv6 Multicast Interface Table is empty
IPv6 Multicast Forwarding Table is empty
[root@R3]~# netstat -g
IPv4 Virtual Interface Table
Vif Thresh Local-Address Remote-Address Pkts-In Pkts-Out
0 1 10.0.23.3 0 0
1 1 10.0.34.3 0 0
IPv4 Multicast Forwarding Table is empty
IPv6 Multicast Interface Table is empty
IPv6 Multicast Forwarding Table is empty
=> There are VIF for all PIM-DM enabled interface
Does PIM daemon locally register to PIM mcast group ?¶
PIM router need to register to 224.0.0.13 mcast group, check if all PIM routers correctly display this group on their enabled interfaces:
[root@R2]~# ifmcstat
em0:
inet 10.0.12.2
igmpv2
group 224.0.0.2 mode exclude
mcast-macaddr 01:00:5e:00:00:02
group 224.0.0.13 mode exclude
mcast-macaddr 01:00:5e:00:00:0d
inet6 fe80::a8aa:ff:fe00:212%em0 scopeid 0x1
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff01::1%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::2:1124:9296%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:11:24:92:96
group ff02::2:ff11:2492%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:ff:11:24:92
group ff02::1%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::1:ff00:212%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:ff:00:02:12
inet 10.0.12.2
igmpv2
group 224.0.0.1 mode exclude
mcast-macaddr 01:00:5e:00:00:01
em1:
inet 10.0.23.2
igmpv2
group 224.0.0.2 mode exclude
mcast-macaddr 01:00:5e:00:00:02
group 224.0.0.13 mode exclude
mcast-macaddr 01:00:5e:00:00:0d
inet6 fe80::a8aa:ff:fe02:202%em1 scopeid 0x2
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff01::1%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::2:1124:9296%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:11:24:92:96
group ff02::2:ff11:2492%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:ff:11:24:92
group ff02::1%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::1:ff02:202%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:ff:02:02:02
inet 10.0.23.2
igmpv2
group 224.0.0.1 mode exclude
mcast-macaddr 01:00:5e:00:00:01
[root@R3]~# ifmcstat
em1:
inet 10.0.23.3
igmpv2
group 224.0.0.2 mode exclude
mcast-macaddr 01:00:5e:00:00:02
group 224.0.0.13 mode exclude
mcast-macaddr 01:00:5e:00:00:0d
inet6 fe80::a8aa:ff:fe00:323%em1 scopeid 0x2
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff01::1%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::2:1124:9296%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:11:24:92:96
group ff02::2:ff11:2492%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:ff:11:24:92
group ff02::1%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::1:ff00:323%em1 scopeid 0x2 mode exclude
mcast-macaddr 33:33:ff:00:03:23
inet 10.0.23.3
igmpv2
group 224.0.0.1 mode exclude
mcast-macaddr 01:00:5e:00:00:01
em2:
inet 10.0.34.3
igmpv2
group 224.0.0.2 mode exclude
mcast-macaddr 01:00:5e:00:00:02
group 224.0.0.13 mode exclude
mcast-macaddr 01:00:5e:00:00:0d
inet6 fe80::a8aa:ff:fe03:303%em2 scopeid 0x3
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff01::1%em2 scopeid 0x3 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::2:1124:9296%em2 scopeid 0x3 mode exclude
mcast-macaddr 33:33:11:24:92:96
group ff02::2:ff11:2492%em2 scopeid 0x3 mode exclude
mcast-macaddr 33:33:ff:11:24:92
group ff02::1%em2 scopeid 0x3 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::1:ff03:303%em2 scopeid 0x3 mode exclude
mcast-macaddr 33:33:ff:03:03:03
inet 10.0.34.3
igmpv2
group 224.0.0.1 mode exclude
mcast-macaddr 01:00:5e:00:00:01
We correctly sees mcast group 224.0.0.13 subscribed on PIM enabled interfaces.
Testing¶
Enable IPerf server on R4 (mcast receiver)¶
This IPerf server will listen the 239.1.1.1 multicast group
[root@R4]~# iperf -s -u -B 239.1.1.1 -i 1
------------------------------------------------------------
Server listening on UDP port 5001
Binding to local address 239.1.1.1
Joining multicast group 239.1.1.1
Receiving 1470 byte datagrams
UDP buffer size: 41.1 KByte (default)
------------------------------------------------------------
IPerf client on R1 (mcast sender)¶
Start an iperf client to 239.1.1.1.
[root@R1]~# iperf -c 239.1.1.1 -u -T 32 -t 300 -i 1
------------------------------------------------------------
Client connecting to 239.1.1.1, UDP port 5001
Sending 1470 byte datagrams
Setting multicast TTL to 32
UDP buffer size: 9.00 KByte (default)
------------------------------------------------------------
[ 3] local 10.0.12.1 port 34390 connected with 239.1.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 1.0 sec 128 KBytes 1.05 Mbits/sec
[ 3] 1.0- 2.0 sec 128 KBytes 1.05 Mbits/sec
[ 3] 2.0- 3.0 sec 128 KBytes 1.05 Mbits/sec
[ 3] 0.0- 3.0 sec 385 KBytes 1.05 Mbits/sec
[ 3] Sent 268 datagrams
Now check than R4 receive the iperf trafic send by R1:
Nothing !?
Troubleshooting¶
Multicast table on R2¶
What’s the status of multicast table of the first router:
[root@router]~# netstat -g
IPv4 Virtual Interface Table
Vif Thresh Local-Address Remote-Address Pkts-In Pkts-Out
0 1 10.0.12.2 2799 0
1 1 10.0.23.2 0 0
IPv4 Multicast Forwarding Table
Origin Group Packets In-Vif Out-Vifs:Ttls
10.0.12.1 239.1.1.1 2799 0
IPv6 Multicast Interface Table is empty
IPv6 Multicast Forwarding Table is empty
=> it correctly detect a multicast source comming from VIF 0 (em0) but didn’t forward packet toward R3: Why ?
Using R3 as a subscriber¶
Starting an iperf receiver on R3 and check if it received mcast traffic by re-starting ipferf on R1.
Status of mcast routing table on R2:
[root@R2]~# netstat -g
IPv4 Virtual Interface Table
Vif Thresh Local-Address Remote-Address Pkts-In Pkts-Out
0 1 10.0.12.2 5516 0
1 1 10.0.23.2 0 162
IPv4 Multicast Forwarding Table
Origin Group Packets In-Vif Out-Vifs:Ttls
10.0.12.1 239.1.1.1 162 0 1:1
IPv6 Multicast Interface Table is empty
IPv6 Multicast Forwarding Table is empty
=> R2 correctly received AND forward mcast traffic from VIF0 (em0) to VIF1 (em1)
and R3 correctly receive mcast traffic:
------------------------------------------------------------
[ 3] local 239.1.1.1 port 5001 connected with 10.0.12.1 port 11166
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 3] 0.0- 1.0 sec 128 KBytes 1.05 Mbits/sec 0.175 ms 0/ 89 (0%)
[ 3] 1.0- 2.0 sec 128 KBytes 1.05 Mbits/sec 0.251 ms 0/ 89 (0%)
[ 3] 2.0- 3.0 sec 128 KBytes 1.05 Mbits/sec 0.189 ms 0/ 89 (0%)
[ 3] 3.0- 4.0 sec 128 KBytes 1.05 Mbits/sec 0.165 ms 0/ 89 (0%)
[ 3] 4.0- 5.0 sec 128 KBytes 1.05 Mbits/sec 0.268 ms 0/ 89 (0%)
[ 3] 5.0- 6.0 sec 128 KBytes 1.05 Mbits/sec 0.243 ms 0/ 89 (0%)
[ 3] 6.0- 7.0 sec 129 KBytes 1.06 Mbits/sec 0.199 ms 0/ 90 (0%)
[ 3] 7.0- 8.0 sec 128 KBytes 1.05 Mbits/sec 0.187 ms 0/ 89 (0%)
=> Need to found why R2 didn’t forward traffic to a next-hop-PIM router.
To dig, error on R2 pimd daemon:
Jun 7 09:22:48 router pimdd[1483]: warning - sendto from 10.0.12.2 to 224.0.0.13: Invalid argument
Jun 7 09:22:48 router pimdd[1483]: warning - sendto from 10.0.23.2 to 224.0.0.13: Invalid argument
Jun 7 09:23:07 router pimdd[1483]: warning - received packet from 10.0.23.3 shorter (48 bytes) than hdr+data length (24+12264)
Jun 7 09:23:07 router pimdd[1483]: warning - received packet from 10.0.23.3 shorter (48 bytes) than hdr+data length (24+12264)
Jun 7 09:23:17 router pimdd[1483]: warning - sendto from 10.0.12.2 to 224.0.0.13: Invalid argument
Jun 7 09:23:17 router pimdd[1483]: warning - sendto from 10.0.23.2 to 224.0.0.13: Invalid argument
This problem is linked to the FreeBSD SOCK_RAW recent changes.