9 Oct
2013
9 Oct
'13
2:42 a.m.
Rob Janssen wrote:
Checking the kernel sources I found that besides the IP_ADD_MEMBERSHIP call to
setsockopt, another option exists: MCAST_JOIN_GROUP which receives a group_req
struct (instead of ip_mreq) which includes a gr_interface member, an interface
index which can be filled using if_nametoindex(ifname).
So, if the call is changed in ampr-ripd, it can uniquely add the multicast address to the
correct interface (which is already known in ampr-ripd).
Marius ? What about changing this?
Rob
Subject:
Re: [44net] 44Net Digest, Vol 2, Issue 159
From:
sp2lob <sp2lob(a)tlen.pl>
Date:
10/07/2013 09:49 PM
To:
AMPRNet working group <44net(a)hamradio.ucsd.edu>
Hello Rob et al,
Quote:
"...by default mcast routes will be associated with an interface
the kernel picks (usually the first to come up)."
There is something what you're looking for, I believe.
Small, nifty & powerfull program to install: *smcroute*
The *smcroute* <http://www.cschill.de/smcroute/> utility provides a command line
interface to manipulate
the multicast routing tables via a method other than *mrouted*.
Tom,
I looked in the source and this tool is not going to fix it.
It uses exactly the same setsockopt call that ampr-ripd is already using to join the
multicast group.
The problem is that this setsockopt has 2 IP address parameters, one is the address
of the local interface and the other is the multicast group to join.
This is of course wrong. The first should not be an IP address but an interface name.
But this kernel interface appears to be very old, dating back from BSD Unix.