Continued network problems

[Krsnendu dasa]

2008/6/24 Gavin McCullagh <gmccullagh at gmail.com>:
> Hi,
>
> On Mon, 23 Jun 2008, Krsnendu dasa wrote:
>
>> The main problem is that dhcp sometimes works and sometimes doesn't.
>> e.g. Sometimes 5 terminals boot up at once and then the 6th won't.
>> Then later it will boot.
>
> If you run this on the client:
>
>        sudo tcpdump -i eth3 port 67 or port 68
>
> you should be able to see the dhcp requests from the client and responses.
> You can therefore see if your server is responding to each request it gets
> and how quickly.
>

First I ran the command you gave. Then I started a terminal.
I repeatedly started the terminal until it booted about 5 mins later.

krsnendu at hks1:~$ sudo tcpdump -i eth4 port 67
[sudo] password for krsnendu:
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth4, link-type EN10MB (Ethernet), capture size 96 bytes
10:17:51.262022 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:18:16.294813 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:18:25.295097 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:18:26.275469 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:18:28.252868 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:18:32.207705 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:18:36.310819 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:18:40.117345 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:18:46.338814 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:18:56.346829 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:19:01.450391 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:19:02.445640 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:19:04.423045 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:19:06.354837 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:19:08.377880 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:19:16.287526 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:19:26.370829 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:19:41.382823 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:19:51.391352 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:20:01.399365 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:20:16.567358 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:20:36.583341 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:20:46.591360 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:20:56.630858 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:21:06.686840 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:24:13.318782 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:24:14.001725 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:24:14.300081 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:24:14.300162 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:24:16.277507 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:24:16.277695 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:24:20.232346 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 548
10:24:20.239244 IP hks1.harekrishna.school.nz.bootps >
255.255.255.255.bootpc: BOOTP/DHCP, Reply, length 300
10:24:37.655990 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 271

# Here it finally gets an ip address and boots.
# I don't know what has changed?????

10:24:37.656114 IP hks1.harekrishna.school.nz.bootps >
192.168.0.94.bootpc: BOOTP/DHCP, Reply, length 309
10:24:37.656447 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 283
10:24:37.664520 IP hks1.harekrishna.school.nz.bootps >
192.168.0.94.bootpc: BOOTP/DHCP, Reply, length 309
10:24:39.664229 IP 0.0.0.0.bootpc > 255.255.255.255.bootps:
BOOTP/DHCP, Request from 00:08:c7:a3:cb:8e (oui Unknown), length 283
10:24:41.865815 IP hks1.harekrishna.school.nz.bootps >
192.168.0.94.bootpc: BOOTP/DHCP, Reply, length 309

>> Dhcp also takes a long time to restart when I do it from the command
>> line. Like 2 mins or so.
>
>  - If you stop it and then separately start it, which takes the time or is
>   it split between the two?
It stops and starts slowly. About equal.

>  - Are there any logs in /var/log/syslog which suggest a problem with
>   dhcpd.
>  - What is the load on the machine (the output of the uptime command will
>   tell you)?

krsnendu at hks1:~$ uptime
 10:36:52 up  1:09,  6 users,  load average: 0.06, 0.05, 0.09

>  - During the minute, if you run "top" does dhcpd appear near the top?

No. Can't see it anywhere and the overall load is not high.
>
>> (It is running from eth3 because eth0 and eth1 are from the previous
>> motherboard setup.)
>
> You probably need to comment out the entries in /etc/iftab to solve this.
> Then things will fall back to eth0. eth1, etc.

I am now on eth0 because I am on a new motherboard. Couldn't find /etc/iftab
is there another file?

Thanks for the help. Hopefully we can get to the bottom of it.

Krsnendu dasa