UDP multicast packets not seen on listening interface in BETA5

Josh Carroll josh.carroll at gmail.com
Thu Sep 29 15:37:59 PDT 2005


Bill -

my apologies, I should have included that information. The NIC
connected to the modem is fxp0, the NIC for the LAN is an em0. fxp0 is
what I want to send the IGMP packets on, and on which I am listening
for the modem's information. Specifically, the alias on fxp0 is
192.168.1.1 with netmask 255.255.255.0. The modem is on 192.168.1.254.

Robert -

there are actually two phases. The first phase is running the "wstart"
program which sends  broadcast packets to turn the modem stats "on",
and then joins the the multicast group. It is not binding to a
particular interface or IP:

iphdr->ip_src.s_addr = INADDR_ANY;
...
igmphdr->igmp_type = IGMP_V2_MEMBERSHIP_REPORT;

And looking at tcpdump output while running wstart indicates it is
binding to the default IP (fxp0's IP):

15:22:04.883779 IP deblin.org > IGMP.MCAST.NET: igmp v2 report 224.73.193.62

Likewise, the westell program that listens for the packets does not
bind to a particular interface or IP:

server.sin_addr.s_addr=htonl(INADDR_ANY);

The output from netstat -ia doesn't look to be much different between
the two. Here is the output of netstat -ia on BETA5:

Name    Mtu Network       Address              Ipkts Ierrs    Opkts Oerrs  Coll
em0    1500 <Link#1>      00:0e:0c:6c:b9:16   298873     0   473687     0     0
                          33:33:f7:e8:2f:a9      746          11324
                          33:33:00:00:00:01      746          11324
                          33:33:ff:6c:b9:16      746          11324
                          01:00:5e:00:00:01      746          11324
em0    1500 10/24         10.0.0.1            289957     -   453474     -     -
                          ALL-SYSTEMS.MCAST
em0    1500 fe80:1::20e:c fe80:1::20e:cff:f        0     -        4     -     -
                          ff02:1::2:f7e8:2fa9(refs: 1)
                          ff02:1::1          (refs: 1)
                          ff02:1::1:ff6c:b916(refs: 1)
em0    1500 10.0.1/24     10.0.1.1               181     -        0     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 <Link#2>      00:a0:c9:1f:ac:f8   102256     0    80348     0    11
                          33:33:f7:e8:2f:a9    12321             10
                          33:33:00:00:00:01    12321             10
                          33:33:ff:1f:ac:f8    12321             10
                          01:00:5e:00:00:01    12321             10
fxp0   1500 66.218.55/24  deblin               71482     -    72916     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 fe80:2::2a0:c fe80:2::2a0:c9ff:        0     -        4     -     -
                          ff02:2::2:f7e8:2fa9(refs: 1)
                          ff02:2::1          (refs: 1)
                          ff02:2::1:ff1f:acf8(refs: 1)
fxp0   1500 66.218.55/24  f00f.deblin           1522     -        0     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 66.218.55/24  spoon.matrixdecod     7811     -      799     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 66.218.55/24  efnet-linux.debli     1782     -       28     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 192.168.1     192.168.1.1            221     -      220     -     -
                          ALL-SYSTEMS.MCAST
pflog 33208 <Link#3>                               0     0        0     0     0
lo0   16384 <Link#4>                            3391     0     3391     0     0
lo0   16384 your-net      localhost              470     -      470     -     -
                          ALL-SYSTEMS.MCAST
lo0   16384 ip6-localhost ::1                      0     -        0     -     -
                          ff01::1            (refs: 1)
                          ff02:4::2:f7e8:2fa9(refs: 1)
                          ff02:4::1          (refs: 1)
                          ff02:4::1:ff00:1   (refs: 2)
lo0   16384 fe80:4::1     fe80:4::1                0     -        0     -     -
                          ff01::1            (refs: 1)
                          ff02:4::2:f7e8:2fa9(refs: 1)
                          ff02:4::1          (refs: 1)
                          ff02:4::1:ff00:1   (refs: 2)
bridg  1500 <Link#5>      ac:de:48:62:36:8d    13594     0   554055     0     0

And the output on BETA3:

Name    Mtu Network       Address              Ipkts Ierrs    Opkts Oerrs  Coll
em0    1500 <Link#1>      00:0e:0c:6c:b9:16       62     0      127     0     0
                          33:33:f7:e8:2f:a9        3             62
                          33:33:00:00:00:01        3             62
                          33:33:ff:6c:b9:16        3             62
                          01:00:5e:00:00:01        3             62
em0    1500 10/24         10.0.0.1               117     -      117     -     -
                          ALL-SYSTEMS.MCAST
em0    1500 fe80:1::20e:c fe80:1::20e:cff:f        0     -        3     -     -
                          ff02:1::2:f7e8:2fa9(refs: 1)
                          ff02:1::1          (refs: 1)
                          ff02:1::1:ff6c:b916(refs: 1)
em0    1500 10.0.1/24     10.0.1.1                 1     -        0     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 <Link#2>      00:a0:c9:1f:ac:f8     1409    24      937     0     0
                          33:33:f7:e8:2f:a9       63              6
                          33:33:00:00:00:01       63              6
                          33:33:ff:1f:ac:f8       63              6
                          01:00:5e:00:00:01       63              6
fxp0   1500 66.218.55/24  deblin                 678     -      909     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 fe80:2::2a0:c fe80:2::2a0:c9ff:        0     -        3     -     -
                          ff02:2::2:f7e8:2fa9(refs: 1)
                          ff02:2::1          (refs: 1)
                          ff02:2::1:ff1f:acf8(refs: 1)
fxp0   1500 66.218.55/24  f00f.deblin            180     -        0     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 66.218.55/24  spoon.matrixdecod        0     -        0     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 66.218.55/24  efnet-linux.debli      147     -        0     -     -
                          ALL-SYSTEMS.MCAST
fxp0   1500 192.168.1     192.168.1.1              1     -        0     -     -
                          ALL-SYSTEMS.MCAST
pflog 33208 <Link#3>                               0     0        0     0     0
lo0   16384 <Link#4>                             152     0      152     0     0
lo0   16384 your-net      localhost                8     -        8     -     -
                          ALL-SYSTEMS.MCAST
lo0   16384 ip6-localhost ::1                      0     -        0     -     -
                          ff01::1            (refs: 1)
                          ff02:4::2:f7e8:2fa9(refs: 1)
                          ff02:4::1          (refs: 1)
                          ff02:4::1:ff00:1   (refs: 2)
lo0   16384 fe80:4::1     fe80:4::1                0     -        0     -     -
                          ff01::1            (refs: 1)
                          ff02:4::2:f7e8:2fa9(refs: 1)
                          ff02:4::1          (refs: 1)
                          ff02:4::1:ff00:1   (refs: 2)
bridg  1500 <Link#5>      ac:de:48:dd:10:32       66     0     1100     0     0

Thanks again,
Josh


More information about the freebsd-current mailing list