Multiple NIC Hosts

[Tom Elliott]

so apparently this isn’t working properly.

I’ve changed the for loop to only add if the interfaces found does not match lo and eth0. My testing side seems to work properly, but other’s are seeing really strange things, particularly that the nic’s aren’t getting IPs. I don’t know why, maybe I can get some help over here?

[Sebastian Roth]

Sure I am happy to assist as much as I can!! Looking at the script in current SVN I noticed that you create ‘/etc/network/interfaces’ new from scratch (by using ‘>’) when ‘lo’ is detected. Normally that would be a good idea but when running this in my FOG test environment (QEMU) I end up with this:
[CODE]auto lo
iface lo inet loopback[/CODE]

Why you ask?? Because ‘lo’ does not necessarily come first. Actually on most systems ls is sorted by alphabet and ‘e’ comes before ‘l’. Do you know what I mean?

Fix: Use “>> /etc/network/interfaces” everywhere instead of “> /etc/network/interfaces”. If you want to make sure that it’s empty then do “echo > /etc/network/interfaces” before the for loop.

[cspence]

By default, udhcpc uses eth0. You will probably need to add -a $iface to udhcpc_opts. I was unsure if that would be taken care of by /etc/network/interfaces.

[Tom Elliott]

What’s weird, though, is the /etc/network/interfaces appears to get the proper values set (without the -a) but even without eth0 should still be found with little issue, and without these tweaks (reverting back to only having iface eth0) everything functions properly.

[cspence]

[quote=“Tom Elliott, post: 43023, member: 7271”]What’s weird, though, is the /etc/network/interfaces appears to get the proper values set (without the -a) but even without eth0 should still be found with little issue, and without these tweaks (reverting back to only having iface eth0) everything functions properly.[/quote]

Actually, I was trying to go off memory. The flag is [B]-i $iface[/B]. You don’t want to use -a. Sorry about that.

[Tom Elliott]

Updated to reflect the change. Pushed to inits as well.

[Tom Elliott]

Would the problems we’re seeing be related to the fact we bring the interface up, but we don’t bring it back down, so when the interface is added and the loop happens, it can’t get dhcp because it believes the link is up?

[cspence]

Finally got a chance to play with it, and I have a solution.

Insert a 5-second sleep between setting the interface up and checking the link status (we can’t just check before it gets a chance to find out if it is connected to a cable). Here’s the snippet as modified.

[CODE]…
/sbin/ip link set $iface up

Provide time for the interface to update linkstate

sleep 5
linkstate=$(/bin/cat /sys/class/net/$iface/carrier)
…[/CODE]

Works on my end.

…and if you wait just a second, I’ll have an optimized version…

[cspence]

[CODE]# Enable all interfaces
ifaces=$(ls -1 /sys/class/net | tr -d ‘@’)
for iface in $ifaces; do
/sbin/ip link set $iface up
done

Provide time for interfaces to detect their state

sleep 5

echo “auto lo” > /etc/network/interfaces
echo “iface lo inet loopback” >> /etc/network/interfaces

for iface in $ifaces; do
linkstate=$(/bin/cat /sys/class/net/$iface/carrier)
if [[ “x$linkstate” = “x1” -a “x$iface” != “xlo” ]]; then
echo “auto $iface” >> /etc/network/interfaces
echo “iface $iface inet dhcp” >> /etc/network/interfaces
echo -e “\tudhcpc_opts -t 100 -T 20\n” >> /etc/network/interfaces
fi
/sbin/ip link set $iface down
done[/CODE]

This solution only requires one sleep rather than five-seconds of sleep time per interface.

Edit: Fixed typos.

[Tom Elliott]

Bad statement.

linkstate=$(/bin/cat /sys/class/net/$iface

Should be
linkstate=$(/bin/cat /sys/class/net/$iface)

[Tom Elliott]

Also, shouldn’t the tr -d be tr -d ‘@’ not tr -d ‘0’?

[cspence]

[quote=“Tom Elliott, post: 43117, member: 7271”]Also, shouldn’t the tr -d be tr -d ‘@’ not tr -d ‘0’?[/quote]

Sorry, I was copying off code from my cellphone and wasn’t thinking about what I was typing. Also caught another typo on the udhcpc_opt statement.

Fixed the typos in the original post.

[Tom Elliott]

There’s one more issue

Shouldn’t the cat be reading a file, not the directory?

[cspence]

[quote=“Tom Elliott, post: 43128, member: 7271”]There’s one more issue

Shouldn’t the cat be reading a file, not the directory?[/quote]

Yes. Fixed again. I really should have slept more last night.

[Tom Elliott]

It’s all good, you should see the issues I forget about, like using my mac address implicitly in the inventory and wondering why everybody else is getting repeated inventory errors.

[cspence]

[quote=“Tom Elliott, post: 43130, member: 7271”]It’s all good, you should see the issues I forget about, like using my mac address implicitly in the inventory and wondering why everybody else is getting repeated inventory errors.[/quote]

Now that’s a good one.

[Sebastian Roth]

Thank you guys for working on this and making it all run smoothly!