On 2014-02-01 01:36, tsu2 wrote:
>
> robin_listas;2621099 Wrote:
>> I tried local connections (LAN), both directions. No problems.
>> I’m not sure if they use the GW or go direct, though. Not sure how to
>> find out.
> 
>
> Hook up a packet sniffer and capture what really is happening.
> And, communicating through both NICs is a hit/miss thing. Eventually
> something will fail.
Mmm.
It is not that complicated, after all, a traceroute is good enough
Only that traceroute defaults fail on my network, filtered port. Using
the “-I” option makes it work.
It goes direct, not via the gateway.
minas-tirith:~ # traceroute -I telcontar
traceroute to telcontar (192.168.1.14), 30 hops max, 60 byte packets
1 Elessar.valinor (192.168.1.14) 0.195 ms 0.182 ms 0.178 ms
minas-tirith:~ #
One hop.
And I’m doing this remotely from another computer, with both nics
connected :-p
The system knows which interface to use. Forcing it may cause problems:
minas-tirith:~ # traceroute -I -i eth0 telcontar
traceroute to telcontar (192.168.1.14), 30 hops max, 60 byte packets
1 Elessar.valinor (192.168.1.14) 0.207 ms 0.193 ms 0.187 ms
minas-tirith:~ # traceroute -I -i wlan0 telcontar
traceroute to telcontar (192.168.1.14), 30 hops max, 60 byte packets
1 * * *
2 * * *
3 * * *
4 * * *
5 * * *
> minas-tirith:~ # ping -c 2 -I eth0 telcontar
> PING Telcontar.valinor (192.168.1.14) from 192.168.1.31 eth0: 56(84) bytes of data.
> 64 bytes from Elessar.valinor (192.168.1.14): icmp_seq=1 ttl=64 time=0.126 ms
> 64 bytes from Elessar.valinor (192.168.1.14): icmp_seq=2 ttl=64 time=0.330 ms
>
> --- Telcontar.valinor ping statistics ---
> 2 packets transmitted, 2 received, 0% packet loss, time 999ms
> rtt min/avg/max/mdev = 0.126/0.228/0.330/0.102 ms
> minas-tirith:~ # ping -c 2 -I wlan0 telcontar
> PING Telcontar.valinor (192.168.1.14) from 192.168.1.31 wlan0: 56(84) bytes of data.
> 64 bytes from Elessar.valinor (192.168.1.14): icmp_seq=1 ttl=64 time=0.977 ms
> 64 bytes from Elessar.valinor (192.168.1.14): icmp_seq=2 ttl=64 time=1.03 ms
>
> --- Telcontar.valinor ping statistics ---
> 2 packets transmitted, 2 received, 0% packet loss, time 1001ms
> rtt min/avg/max/mdev = 0.977/1.005/1.033/0.028 ms
> minas-tirith:~ #
> So, if you want <reliable> networking you should only connect <one> NIC
> to the network unless you’re doing something advanced like bonding NICs.
Have a bit more trust - network manager defaults should work for most
people Many people use laptops with NM, and have both cable and
wlan. Many people will have been in the situation of both interfaces
connected (accidentally or intentionally), and if it did not work the
complains would be humongous.
I’ve been connecting and disconnecting it several times during the
afternoon, with services running in both directions, and I did not
detect any problems.
But it is very easy to click on NM to just disable one of the connections.
Yes, it would be nice if it had rules to automatically disconnect wifi
when cable is connected and things like that.
–
Cheers / Saludos,
Carlos E. R.
(from 12.3 x86_64 “Dartmouth” at Telcontar)