Environment: Two servers connected through a router, both running Ubuntu 16.04 I use the following commands to disable multicast:ifconfig eno1 -multicastorip link set eno1 multicast offAnd check the result, no multicast flag:$ ifconfig eno1eno1      Link encap:Ethernet  HWaddr f8:ca:b8:4b:5b:88            inet addr:192.168.1.240  Bcast:192.168.1.255  Mask:255.255.255.0          inet6 addr: fe80::34c4:560f:208a:9249/64 Scope:Link          UP BROADCAST RUNNING  MTU:1500  Metric:1          RX packets:193 errors:0 dropped:0 overruns:0 frame:0          TX packets:742 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:1000           RX bytes:39493 (39.4 KB)  TX bytes:602751 (602.7 KB)          Interrupt:20 Memory:f7200000-f7220000 Then I use iperf to test multicast,One server sends packages:$ iperf -c 226.94.1.1 -u -i 1Another server still receives packages:$ iperf -s -u -B 226.94.1.1 -i 1------------------------------------------------------------Server listening on UDP port 5001Binding to local address 226.94.1.1Joining multicast group  226.94.1.1Receiving 1470 byte datagramsUDP buffer size:  208 KByte (default)------------------------------------------------------------[  3] local 226.94.1.1 port 5001 connected with 192.168.1.240 port 36855[ ID] Interval       Transfer     Bandwidth        Jitter   Lost/Total Datagrams[  3]  0.0- 1.0 sec   128 KBytes  1.05 Mbits/sec   0.002 ms    0/   89 (0%)[  3]  1.0- 2.0 sec   128 KBytes  1.05 Mbits/sec   0.002 ms    0/   89 (0%)It seems multicast mode not disabled.I don't know why.Thanks for any help.
Cannot disable multicast in linux
linux;multicast