Multiple NIC Hosts

[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!