Rick,

I don't see any way around this.  For example, on one of my test
systems, I have the following link local routes:

chance% netstat -A inet6 -rn | grep fe80::/64
fe80::/64                                   ::                                  
    U     256    0        0 eth0
fe80::/64                                   ::                                  
    U     256    0        0 eth2
fe80::/64                                   ::                                  
    U     256    0        0 eth3
fe80::/64                                   ::                                  
    U     256    0        0 eth4
fe80::/64                                   ::                                  
    U     256    0        0 eth5
fe80::/64                                   ::                                  
    U     256    0        0 eth6

So if I want to run a link local test to fe80::202:b3ff:fed4:cd1,
the system has no way to choose which is the correct interface to
use for the test, and will give an error if the interface isn't
specified.

Yeah, I was wondering about that. I'm not sure if the attempts on "those other OSes" happened to involve multiple interfaces or not. Even so, it "feels" unpleasant for an application to deal with and I wonder if there is a way for a stack to deal with it on the application's behalf. I guess that might involve some sort of layer violation between neightbor discovery and routing (typing while I think about things I know little about...)

Is there RFC chapter and verse I might read about routing with multiple link-local's on a system?

You must explicitly specify the desired interface.  For example,
on my test system, the correct interface is eth6 which is interface 8
(lo eth0 eth1 eth2 ... eth5 eth6).  Here is an example nuttcp test
specifying interface 8:

chance% nuttcp -P5100 fe80::202:b3ff:fed4:cd1%8
 1178.5809 MB /  10.02 sec =  986.2728 Mbps 12 %TX 15 %RX

nuttcp uses getaddrinfo() which parses the "%<ifindex>" field,
and then copies the sin6_scope_id from the res structure to the
server's sockaddr_in6 structure before initiating the connect().

OK, I'll give that a quick try with netperf:

[EMAIL PROTECTED] ~]# netperf -H 192.168.2.107 -c -C -i 30,3 -- -s 1M -S 1M -m 64K -H fe80::207:43ff:fe05:9d%2 TCP STREAM TEST from ::0 (::) port 0 AF_INET6 to fe80::207:43ff:fe05:9d%2 (fe80::207:43ff:fe05:9d) port 0 AF_INET6 : +/-2.5% @ 99% conf.

Cool - it establishes the data connection just fine.


To further demonstrate my ignorance :) is that %n suffix something one might expect in most/all getaddrinfo()'s or is that unique to the one in Linux?

rick jones
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