documentation:examples:multicast_with_pim-sm
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Table of Contents
Multicast with PIM-SM
This lab show a multicast routing example using PIM in Sparse Mode.
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:
tools/BSDRP-lab-bhyve.sh -n 4 -i BSDRP-2.0-full-amd64.img.xz BSD Router Project (https://bsdrp.net) - bhyve full-meshed lab script Setting-up a virtual lab with 4 VM(s): - Working directory: /home/olivier/BSDRP-VMs - Each VM has a total of 1 (1 cores and 1 threads) and 1G RAM - Emulated NIC: virtio-net - Boot mode: UEFI - Switch mode: bridge + tap - 0 LAN(s) between all VM - Full mesh Ethernet links between each VM VM 1 has the following NIC: - vtnet0 connected to VM 2 - vtnet1 connected to VM 3 - vtnet2 connected to VM 4 VM 2 has the following NIC: - vtnet0 connected to VM 1 - vtnet1 connected to VM 3 - vtnet2 connected to VM 4 VM 3 has the following NIC: - vtnet0 connected to VM 1 - vtnet1 connected to VM 2 - vtnet2 connected to VM 4 VM 4 has the following NIC: - vtnet0 connected to VM 1 - vtnet1 connected to VM 2 - vtnet2 connected to VM 3 To connect VM'serial console, you can use: - VM 1 : sudo cu -l /dev/nmdm-BSDRP.1B - VM 2 : sudo cu -l /dev/nmdm-BSDRP.2B - VM 3 : sudo cu -l /dev/nmdm-BSDRP.3B - VM 4 : sudo cu -l /dev/nmdm-BSDRP.4B
Routers configuration
Router 1
Configuration:
sysrc hostname=VM1 \ gateway_enable=no \ ipv6_gateway_enable=no \ ifconfig_vtnet0="inet 10.0.12.1/24" \ defaultrouter=10.0.12.254 service hostname restart service netif restart service routing restart config save
Router 2
VM2 is a PIM router that announce itself (10.0.23.2) as Canditate RP with and adv period of 10 seconds and high priority (will be the rendez-vous point).
sysrc hostname=VM2 \ ifconfig_vtnet0="inet 10.0.12.254/24" \ ifconfig_vtnet1="inet 10.0.23.2/24" \ defaultrouter=10.0.23.3 \ pimd_enable=yes cat > /usr/local/etc/pimd.conf <<EOF rp-candidate 10.0.23.2 time 10 priority 1 #rp-address 10.0.23.2 EOF service hostname restart service netif restart service routing restart service pimd start config save
Router 3
We would VM3 annonces hitself (10.0.23.3) as a Canditate BootStrap Router with high priority.
sysrc hostname=VM3 \ ifconfig_vtnet1="inet 10.0.23.3/24" \ ifconfig_vtnet2="inet 10.0.34.254/24" \ defaultrouter=10.0.23.2 \ pimd_enable=yes cat > /usr/local/etc/pimd.conf <<EOF bsr-candidate 10.0.23.3 priority 1 #rp-address 10.0.23.2 EOF service hostname restart service netif restart service routing restart service pimd start config save
Router 4
sysrc hostname=VM4 \ gateway_enable=no \ ipv6_gateway_enable=no \ ifconfig_vnet2="inet 10.0.34.4/24" \ defaultrouter=10.0.34.254 service hostname restart service netif restart service routing restart config save
Checking NIC drivers and Bhyve compatibility with multicast
Before to star with advanced routing setup, just start to test simple multicast between 2 relatives host: Some NIC (vtnet) or some hypervisors network setup aren't compliant with very simple multicast.
On VM1, start a mcast generator (client emitting mcast):
[root@VM1]~# iperf -c 239.1.1.1 -u -T 32 -t 3000 -i 1 ------------------------------------------------------------ Client connecting to 239.1.1.1, UDP port 5001 Sending 1470 byte datagrams, IPG target: 11215.21 us (kalman adjust) Setting multicast TTL to 32 UDP buffer size: 9.00 KByte (default) ------------------------------------------------------------ [ 3] local 10.0.12.1 port 46636 connected with 239.1.1.1 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0- 1.0 sec 131 KBytes 1.07 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- 3.5 sec 446 KBytes 1.05 Mbits/sec [ 3] Sent 311 datagrams (...)
On the direct connected VM2, start to check if in non-promiscious mode it sees mcast packets comming:
[root@VM2]~# tcpdump -pni vtnet0 -c 2 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on vtnet0, link-type EN10MB (Ethernet), capture size 262144 bytes 15:22:32.517270 IP 10.0.12.1.33482 > 239.1.1.1.5001: UDP, length 1470 15:22:32.528668 IP 10.0.12.1.33482 > 239.1.1.1.5001: UDP, length 1470 2 packets captured 2 packets received by filter 0 packets dropped by kernel
⇒ VM2 is receiving mcast packets from 10.0.12.1 to mcast group 239.1.1.1. Now on VM2 start a mcast listener (server receiving), it should receive multicast flow
[root@VM2]~# iperf -s -u -B 239.1.1.1%vtnet0 -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) ------------------------------------------------------------ [ 3] local 239.1.1.1 port 5001 connected with 192.168.100.149 port 35181 [ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams [ 3] 0.0- 1.0 sec 129 KBytes 1.06 Mbits/sec 0.038 ms 107/ 197 (54%) [ 3] 1.0- 2.0 sec 128 KBytes 1.05 Mbits/sec 0.054 ms 0/ 89 (0%) [ 3] 2.0- 3.0 sec 128 KBytes 1.05 Mbits/sec 0.021 ms 0/ 89 (0%) [ 3] 3.0- 4.0 sec 128 KBytes 1.05 Mbits/sec 0.025 ms 0/ 89 (0%) [ 3] 4.0- 5.0 sec 128 KBytes 1.05 Mbits/sec 0.024 ms 0/ 89 (0%) [ 3] 5.0- 6.0 sec 129 KBytes 1.06 Mbits/sec 0.024 ms 0/ 90 (0%) [ 3] 6.0- 7.0 sec 128 KBytes 1.05 Mbits/sec 0.024 ms 0/ 89 (0%) (...)
⇒ Notice the mcast receiver is correctly receiving at 1Mb/s.
Here is a non working example (here because source interface not given, and it uses the other one):
[root@VM2]~# 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) ------------------------------------------------------------ (...)
⇒ Here it doesn't receive traffic and stay in “waiting” mode forever.
Checking pimd behavior
PIM neighbors
Does the PIM routers see each others ?
root@VM2:~ # pimctl show PIM Interface Table Interface State Address Priority Hello Nbr DR Address DR Priori ty vtnet0 Up 10.0.12.2 1 30 0 10.0.12.2 1 vtnet1 Up 10.0.23.2 1 30 1 10.0.23.3 1 PIM Neighbor Table Interface Address Priority Mode Uptime/Expires em1 10.0.23.3 1 DR 0h2m51s/0h1m25s Multicast Routing Table Source Group RP Address Flags 10.0.12.1 239.1.1.1 10.0.23.2 SG Number of Groups : 1 Number of Cache MIRRORs : 0 PIM Candidate Rendez-Vous Point Table Group Address RP Address Prio Holdtime Expires 232.0.0.0/8 169.254.0.1 1 Forever Never 224.0.0.0/4 10.0.23.2 1 150 0h1m45s Current BSR address: 10.0.23.3 PIM Rendez-Vous Point Set Table Group Address RP Address Prio Holdtime Type 232.0.0.0/8 169.254.0.1 1 Forever Static 224.0.0.0/4 10.0.23.2 1 105 Dynamic
⇒ VM2 sees VM3 as PIM neighbor
root@VM3:~ # pimctl show PIM Interface Table Interface State Address Priority Hello Nbr DR Address DR Priori ty vtnet1 Up 10.0.23.3 1 30 1 10.0.23.3 1 vtnet2 Up 10.0.34.3 1 30 0 10.0.34.3 1 PIM Neighbor Table Interface Address Priority Mode Uptime/Expires vtnet1 10.0.23.2 1 0h3m55s/0h1m15s Multicast Routing Table Source Group RP Address Flags Number of Groups : 0 Number of Cache MIRRORs : 0 PIM Candidate Rendez-Vous Point Table Group Address RP Address Prio Holdtime Expires 232.0.0.0/8 169.254.0.1 1 Forever Never 224.0.0.0/4 10.0.23.2 1 150 0h2m25s Current BSR address: 10.0.23.3 PIM Rendez-Vous Point Set Table Group Address RP Address Prio Holdtime Type 232.0.0.0/8 169.254.0.1 1 Forever Static 224.0.0.0/4 10.0.23.2 1 145 Dynamic
⇒ VM3 sees VM2 as PIM Designated Router neighbor.
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@VM2]~# ifmcstat
vtnet0:
inet 10.0.12.2
igmpv2
group 224.0.0.22 refcnt 1 state lazy mode exclude
mcast-macaddr 01:00:5e:00:00:16 refcnt 1
group 224.0.0.2 refcnt 1 state lazy mode exclude
mcast-macaddr 01:00:5e:00:00:02 refcnt 1
group 224.0.0.13 refcnt 1 state lazy mode exclude
mcast-macaddr 01:00:5e:00:00:0d refcnt 1
group 224.0.0.1 refcnt 1 state silent mode exclude
mcast-macaddr 01:00:5e:00:00:01 refcnt 1
inet6 fe80:1::a8aa:ff:fe00:212
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff01:1::1 refcnt 1
mcast-macaddr 33:33:00:00:00:01 refcnt 1
group ff02:1::2:54c6:805c refcnt 1
mcast-macaddr 33:33:54:c6:80:5c refcnt 1
group ff02:1::2:ff54:c680 refcnt 1
mcast-macaddr 33:33:ff:54:c6:80 refcnt 1
group ff02:1::1 refcnt 1
mcast-macaddr 33:33:00:00:00:01 refcnt 1
group ff02:1::1:ff00:212 refcnt 1
mcast-macaddr 33:33:ff:00:02:12 refcnt 1
vtnet1:
inet 10.0.23.2
igmpv2
group 224.0.0.22 refcnt 1 state sleeping mode exclude
mcast-macaddr 01:00:5e:00:00:16 refcnt 1
group 224.0.0.2 refcnt 1 state lazy mode exclude
mcast-macaddr 01:00:5e:00:00:02 refcnt 1
group 224.0.0.13 refcnt 1 state lazy mode exclude
mcast-macaddr 01:00:5e:00:00:0d refcnt 1
group 224.0.0.1 refcnt 1 state silent mode exclude
mcast-macaddr 01:00:5e:00:00:01 refcnt 1
inet6 fe80:2::a8aa:ff:fe02:202
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff01:2::1 refcnt 1
mcast-macaddr 33:33:00:00:00:01 refcnt 1
group ff02:2::2:54c6:805c refcnt 1
mcast-macaddr 33:33:54:c6:80:5c refcnt 1
group ff02:2::2:ff54:c680 refcnt 1
mcast-macaddr 33:33:ff:54:c6:80 refcnt 1
group ff02:2::1 refcnt 1
mcast-macaddr 33:33:00:00:00:01 refcnt 1
group ff02:2::1:ff02:202 refcnt 1
mcast-macaddr 33:33:ff:02:02:02 refcnt 1
[root@VM3]~# ifmcstat
em0:
em1:
inet 10.0.23.3
igmpv2
group 224.0.0.22 refcnt 1 state sleeping mode exclude
mcast-macaddr 01:00:5e:00:00:16 refcnt 1
group 224.0.0.2 refcnt 1 state sleeping mode exclude
mcast-macaddr 01:00:5e:00:00:02 refcnt 1
group 224.0.0.13 refcnt 1 state lazy mode exclude
mcast-macaddr 01:00:5e:00:00:0d refcnt 1
group 224.0.0.1 refcnt 1 state silent mode exclude
mcast-macaddr 01:00:5e:00:00:01 refcnt 1
inet6 fe80:2::a8aa:ff:fe00:323
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff01:2::1 refcnt 1
mcast-macaddr 33:33:00:00:00:01 refcnt 1
group ff02:2::2:1124:9296 refcnt 1
mcast-macaddr 33:33:11:24:92:96 refcnt 1
group ff02:2::2:ff11:2492 refcnt 1
mcast-macaddr 33:33:ff:11:24:92 refcnt 1
group ff02:2::1 refcnt 1
mcast-macaddr 33:33:00:00:00:01 refcnt 1
group ff02:2::1:ff00:323 refcnt 1
mcast-macaddr 33:33:ff:00:03:23 refcnt 1
em2:
inet 10.0.34.3
igmpv2
group 224.0.0.22 refcnt 1 state lazy mode exclude
mcast-macaddr 01:00:5e:00:00:16 refcnt 1
group 224.0.0.2 refcnt 1 state lazy mode exclude
mcast-macaddr 01:00:5e:00:00:02 refcnt 1
group 224.0.0.13 refcnt 1 state lazy mode exclude
mcast-macaddr 01:00:5e:00:00:0d refcnt 1
group 224.0.0.1 refcnt 1 state silent mode exclude
mcast-macaddr 01:00:5e:00:00:01 refcnt 1
inet6 fe80:3::a8aa:ff:fe03:303
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff01:3::1 refcnt 1
mcast-macaddr 33:33:00:00:00:01 refcnt 1
group ff02:3::2:1124:9296 refcnt 1
mcast-macaddr 33:33:11:24:92:96 refcnt 1
group ff02:3::2:ff11:2492 refcnt 1
mcast-macaddr 33:33:ff:11:24:92 refcnt 1
group ff02:3::1 refcnt 1
mcast-macaddr 33:33:00:00:00:01 refcnt 1
group ff02:3::1:ff03:303 refcnt 1
mcast-macaddr 33:33:ff:03:03:03 refcnt 1
We correctly sees mcast group 224.0.0.13 subscribed on PIM enabled interfaces.
Testing
1. Sart a mcast generator (IPerf client) on VM1
Start an iperf client to 239.1.1.1.
[root@VM1]~# iperf -c 239.1.1.1 -u -T 32 -t 3000 -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 41484 connected with 239.1.1.1 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0- 1.0 sec 129 KBytes 1.06 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] 3.0- 4.0 sec 128 KBytes 1.05 Mbits/sec
2. Check VM2 updates its mrouting table with discovered mcast source
PIM daemon should be updated:
[root@VM2]~# pimctl -r pimctl: Sending cmd show: No error: 0 PIM Interface Table Interface State Address Priority Hello Nbr DR Address DR Priority vtnet0 Up 10.0.12.2 1 30 0 10.0.12.2 1 vtnet1 Up 10.0.23.2 1 30 1 10.0.23.3 1 PIM Neighbor Table Interface Address Priority Mode Uptime/Expires vtnet1 10.0.23.3 1 DR 0h8m36s/0h1m40s Multicast Routing Table Source Group RP Address Flags 10.0.12.1 239.1.1.1 10.0.23.2 SPT SG Number of Groups : 1 Number of Cache MIRRORs : 0 PIM Candidate Rendez-Vous Point Table Group Address RP Address Prio Holdtime Expires 232.0.0.0/8 169.254.0.1 1 Forever Never 224.0.0.0/4 10.0.23.2 1 150 0h2m0s Current BSR address: 10.0.23.3 PIM Rendez-Vous Point Set Table Group Address RP Address Prio Holdtime Type 232.0.0.0/8 169.254.0.1 1 Forever Static 224.0.0.0/4 10.0.23.2 1 120 Dynamic
And mcast routing table too:
[root@VM2]~# 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 10.0.12.2 18267 0 2 1 10.0.23.2 0 18267 IPv4 Multicast Forwarding Table Origin Group Packets In-Vif Out-Vifs:Ttls 10.0.12.1 239.1.1.1 0 65535 IPv6 Multicast Interface Table is empty IPv6 Multicast Forwarding Table is empty
VM2 had update its mroute table for adding a source for group 239.1.1.1 coming from '65535'??.
3. Start a mcast receiver (IPerf server) on VM4
IPerf server will subscribe to 239.1.1.1 multicast group and receiving mcast traffic:
[root@VM4]~# 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) ------------------------------------------------------------ [ 3] local 239.1.1.1 port 5001 connected with 10.0.12.1 port 41484 [ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams [ 3] 0.0- 1.0 sec 128 KBytes 1.05 Mbits/sec 0.313 ms 16336/16425 (99%) [ 3] 1.0- 2.0 sec 128 KBytes 1.05 Mbits/sec 0.250 ms 0/ 89 (0%) [ 3] 2.0- 3.0 sec 128 KBytes 1.05 Mbits/sec 0.307 ms 0/ 89 (0%) [ 3] 3.0- 4.0 sec 128 KBytes 1.05 Mbits/sec 0.262 ms 0/ 89 (0%) [ 3] 4.0- 5.0 sec 128 KBytes 1.05 Mbits/sec 0.188 ms 0/ 89 (0%) [ 3] 5.0- 6.0 sec 129 KBytes 1.06 Mbits/sec 0.347 ms 0/ 90 (0%) [ 3] 6.0- 7.0 sec 128 KBytes 1.05 Mbits/sec 0.238 ms 0/ 89 (0%) [ 3] 7.0- 8.0 sec 128 KBytes 1.05 Mbits/sec 0.234 ms 0/ 89 (0%) [ 3] 8.0- 9.0 sec 128 KBytes 1.05 Mbits/sec 0.241 ms 0/ 89 (0%) [ 3] 9.0-10.0 sec 128 KBytes 1.05 Mbits/sec 0.210 ms 0/ 89 (0%) [ 3] 10.0-11.0 sec 128 KBytes 1.05 Mbits/sec 0.289 ms 0/ 89 (0%) [ 3] 11.0-12.0 sec 129 KBytes 1.06 Mbits/sec 0.309 ms 0/ 90 (0%)
4. Check VM3 correctly notice this mcast subscriber
Now the mrouting table of VM3 is updated and know it has a customer:
[root@VM3]~# pimctl -d pimctl: Sending cmd show: No error: 0 PIM Interface Table Interface State Address Priority Hello Nbr DR Address DR Priority vtnet1 Up 10.0.23.3 1 30 1 10.0.23.3 1 vtnet2 Up 10.0.34.3 1 30 0 10.0.34.3 1 PIM Neighbor Table Interface Address Priority Mode Uptime/Expires vtnet1 10.0.23.2 1 0h14m40s/0h1m35s Multicast Routing Table Source Group RP Address Flags ANY 239.1.1.1 10.0.23.2 WC RP 10.0.12.1 239.1.1.1 10.0.23.2 CACHE SG Number of Groups : 1 Number of Cache MIRRORs : 1 PIM Candidate Rendez-Vous Point Table Group Address RP Address Prio Holdtime Expires 232.0.0.0/8 169.254.0.1 1 Forever Never 224.0.0.0/4 10.0.23.2 1 150 0h2m25s Current BSR address: 10.0.23.3 PIM Rendez-Vous Point Set Table Group Address RP Address Prio Holdtime Type 232.0.0.0/8 169.254.0.1 1 Forever Static 224.0.0.0/4 10.0.23.2 1 145 Dynamic
And its mcast routing is updated too:
[root@VM3]~# 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 10.0.23.3 30739 0 2 1 10.0.34.3 0 29215 IPv4 Multicast Forwarding Table Origin Group Packets In-Vif Out-Vifs:Ttls 10.0.12.1 239.1.1.1 29215 1 2:1 IPv6 Multicast Interface Table is empty IPv6 Multicast Forwarding Table is empty
VM3 correctly learn that there is a subscriber to group 239.1.1.1 on interface vif1 (toward VM4) and the source is on vif0 (toward VM2).
documentation/examples/multicast_with_pim-sm.1759420316.txt.gz · Last modified: 2025/10/02 17:51 by olivier