Howto make dhcp work with vlan tagging on slackware?

sysslack · 03-20-2012, 03:58 PM

Hi
I have followed a great guide on VLAN tagging on slackware and made it work
with static ip adress behind a router that can handle VLAN tagging.
DHCP server is also activated for that VLAN. But slackware does not get an valid adress from router, only 169.x.x.x adress. That is why I put a static ip instead in script below.
However it would be nice to configure it for dhcp in file /etc/rc.d/rc.inet1.conf instead of static ip on slackware
Is there a way to do this on slackware for a tagged VLAN?
Here is a script I put in /etc/rc.d/rc.local on slackware 13.37

Code:

vim /etc/rc.d/rc.local
echo "Setting VLAN ..."
modprobe 8021q
vconfig add eth0 10
ifconfig eth0.10 10.0.0.5/24 up
echo "... done"
echo "adding default gateway"
route add default gw 10.0.0.1
echo "... done"
echo "adding dns"
echo "nameserver 8.8.8.8 " >>/etc/resolv.conf
echo "... done

Any Ideas?

Ser Olmy · 03-20-2012, 09:40 PM

You could add the interface name in rc.inet1.conf:

IFNAME[1]="eth0.10"
USE_DHCP[1]="yes"
...

The vconfig command still needs to be run before rc.inet1 is executed. Fortunately, the Slackware startup scripts check for the existence of /etc/rc.d/rc.netdevice and, if the file exists and is executable, runs it prior to calling rc.inet1.

Historically, this script was used to load non-PnP drivers for ISA NICs. In a perfect world, Slackware would have VLAN support in rc.inet1/rc.inet1.conf, but this is an acceptable workaround IMHO. Create /etc/rc.d/rc.netdevice:

#!/bin/sh
/sbin/modprobe 8021q
/sbin/vconfig add eth0 10

Make it executable (chmod u+x /etc/rc.d/rc.netdevice) and you should be good to go.

sysslack · 03-21-2012, 02:52 PM

Thank you
You pointed me in the right direction

Unfortunately it did not work.
error
dhcpcd up_interface network is down

Ser Olmy · 03-21-2012, 03:11 PM

What does ifconfig -a say? Is the host interface (eth0) up? If not, you could try adding ifconfig eth0 up to /etc/rc.d/rc.netdevice.

sysslack · 03-22-2012, 03:12 PM

thank you
I have tried it "ifconfig eth0 up" but it did not work either
ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:1E:EC:68:80:A2
inet addr:169.254.33.56 Bcast:169.254.255.255 Mask:255.255.0.0
inet6 addr: fe80::21e:ecff:fe68:80a2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:210 errors:0 dropped:0 overruns:0 frame:0
TX packets:156 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:20672 (20.1 Kb) TX bytes:28516 (27.8 Kb)

eth0.10 Link encap:Ethernet HWaddr 00:1E:EC:68:80:A2
inet6 addr: fe80::21e:ecff:fe68:80a2/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:180 errors:0 dropped:0 overruns:0 frame:0
TX packets:121 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:16352 (15.9 Kb) TX bytes:22432 (21.9 Kb)

eth1 Link encap:Ethernet HWaddr 00:21:00:20:C6:6E
inet6 addr: fe80::221:ff:fe20:c66e/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:17

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:68 errors:0 dropped:0 overruns:0 frame:0
TX packets:68 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3740 (3.6 Kb) TX bytes:3740 (3.6 Kb)

dmesg |grep eth0
[ 6.393374] e100 0000:02:08.0: eth0: addr 0xf0101000, irq 20, MAC addr 00:1e:ec:68:80:a2
[ 41.040158] e100 0000:02:08.0: eth0: NIC Link is Up 100 Mbps Full Duplex
[ 41.040415] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 41.040598] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 43.234161] e100 0000:02:08.0: eth0: NIC Link is Up 100 Mbps Full Duplex
[ 43.234422] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 43.234604] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 43.262159] e100 0000:02:08.0: eth0: NIC Link is Up 100 Mbps Full Duplex
[ 43.262415] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 43.262597] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 54.098041] eth0: no IPv6 routers present
[ 229.410035] eth0.10: no IPv6 routers present

Ser Olmy · 03-22-2012, 04:13 PM

According to dmesg, the link went up and down several times during the boot process. Unless you physically unplugged and re-inserted the network cable or power cycled the switch/router, this might indicate a layer 1 (physical) problem.

The output from ifconfig says that all links are now up. Have you tried running dhcpcd eth0.10 from the command line? You might want to run tcpdump -i eth0.10 udp port 67 at another console first, to see if the dhcp server responds at all.

sysslack · 03-23-2012, 03:41 AM

Thank you
yes I have tried with dhclient eth0.10 and that worked, but where to put it so it works in a script?
this is the output of tcpdump

Code:

 tcpdump -i -v  eth0.10 udp port 67
tcpdump: -v: No such device exists
(SIOCGIFHWADDR: No such device)

Ser Olmy · 03-23-2012, 01:36 PM

The -i parameter to tcpdump specifies the interface, which in this case is eth0.10. Putting another parameter between -i and the interface name won't work.

It doesn't really matter though, if you've already confirmed that you can indeed get an IP address via DHCP. The problem has to be related to one of the scripts.

You could try inserting a debug statement or two into rc.netdevice and/or rc.inet1 and see what happens at boot. For instance, ifconfig -a at the end of rc.netdevice could be helpful in determining the cause of the problem.

nass · 03-27-2012, 03:45 PM

hello, sorry to intervene, could the OP send us the link to that vlan guide on slackware?

sysslack · 04-01-2012, 06:33 AM

Thank You!
It looks finally as it works:

Code:

tcpdump -i eth0.10 -v udp port 67
tcpdump: listening on eth0.10, link-type EN10MB (Ethernet), capture size 65535 bytes

this is my rc.local:

Code:

echo "Setting VLAN ..."
modprobe 8021q
vconfig add eth0 10
ifconfig eth0.10 up
dhclient eth0.10
echo "... done"
route add default gw 192.168.7.1
echo "adding dns"
echo "nameserver 8.8.8.8  >>/etc/resolv.conf
echo "... done"

this is my rc.inet1.conf:

Code:

# Config information for eth0:
IPADDR[0]=""
NETMASK[0]=""
USE_DHCP[0]="yes"
DHCP_HOSTNAME[0]=""

# Config information for VLAN interface eth0.10:
IFNAME[0]="eth0.10"
USE_DHCP[0]="yes"