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RE: Problem getting DNS server list, no hostname set



brem belguebli wrote:
>Hi there,
>
>I may be addressing this to the wrong ML ?
>
>If so could someone point me to the right one ?
>
>Thanks
>
>Brem
>
>2010/8/13 brem belguebli <brem belguebli gmail com>:
>> Hi,
>>
>> I started anaconda with log=debug to see if I get more information:
>> The dns server option is really trapped but still the same message
>> complaining it can't look up hostname.
>>
>> 09:40:13 DEBUG   : DHCPv4 eth0 - option routers default gateway 0:
>> 192.168.84.254
>> 09:40:13 DEBUG   : DHCPv4 eth0 - option domain-name-servers:
>> 09:40:13 DEBUG   : DHCPv4 eth0 - domain-name-server 0: 10.146.0.11
>> 09:40:13 DEBUG   : DHCPv4 eth0 - domain-name-server 1: 10.146.36.11
>> 09:40:13 DEBUG   : DHCPv4 eth0 - option host-name: testVM
>> 09:40:13 DEBUG   : nic_addr_send: add IFA_ADDRESS: 3
192.168.84.250/24
>>
>> 09:40:13 DEBUG   : nic_addr_send: add IFA_LOCAL: 3 192.168.84.250
>>
>> 09:40:13 DEBUG   : nic_addr_send: add address: 3 broadcast:
>192.168.84.255
>>
>> 09:40:13 ERROR   : no DNS servers, can't look up hostname
>>
>> Any hint or idea ?
>>
>> Thanks
>>
>> 2010/8/12 brem belguebli <brem belguebli gmail com>:
>>> Hi,
>>>
>>> I'm systematically hiting the message "no DNS servers, can't look up
>>> hostname"  while trying to build a hostname based ks file VM
install.
>>>
>>> The PXE server used  is a Rhel 5.4 X86_64, the DHCP service is
offered
>>> by dnsmasq.
>>> The client is a VM expected to be installed with RHEL 5.4.
>>>
>>> When logging dsmasq, I can see that the dns server option (6) is
sent
>>> to the client  as well as the hostname option (12).
>>>
>>> Below the dnsmasq log on the server
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: DHCP packet: transaction-id
>>> is 1664975136
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: Available DHCP range:
>>> 192.168.84.250 -- 192.168.84.251
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: Vendor class: anaconda
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: DHCPREQUEST(br0)
>>> 192.168.84.250 54:52:00:22:92:83
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: DHCPACK(br0) 192.168.84.250
>>> 54:52:00:22:92:83 testVM
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: requested options:
1:netmask,
>>> 28:broadcast, 3:router, 15:domain-name,
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: requested options:
>>> 6:dns-server, 12:hostname, 33:static-route
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: next server: 192.168.84.254
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: bootfile name: pxelinux.0
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: tags: known
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  1 option:
>>> 53:message-type  05
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  4 option:
>>> 54:server-identifier  c0:a8:54:fe
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  4 option:
>>> 51:lease-time  00:00:1c:20
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  4 option: 58:T1
>>> 00:00:0e:10
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  4 option: 59:T2
>>> 00:00:18:9c
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  4 option:
>>> 1:netmask  ff:ff:ff:00
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  4 option:
>>> 28:broadcast  c0:a8:54:ff
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  4 option:
>>> 3:router  c0:a8:54:fe
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  6 option:
>>> 12:hostname  74:65:73:74:56:4d
>>> Aug 12 13:24:16 cmxi1152 dnsmasq[11759]: sent size:  8 option:
>>> 6:dns-server  0a:92:00:0b:0a:92:24:0b
>>>
>>> On client side (console ALT-F3 log)
>>> 11:24:15 INFO     : getting kickstart file
>>> 11:24:15 INFO     : sending dhcp request through device eth0
>>> 11:24:15 INFO     : requesting dhcp timeout 45
>>> 11:24:15 INFO     : Listening on LPF/eth0/54:52:00:22:93:83
>>> 11:24:15 INFO     : Sending on LPF/eth0/54:52:00:22:93:83
>>> 11:24:15 INFO     : Sending on Socket/fallback
>>> 11:24:15 INFO     : DHCPDISCOVER on eth0 to 255.255.255.255 port 67
>interval 5
>>> 11:24:15 INFO     : DHCPOFFER from 192.168.84.254
>>> 11:24:15 INFO     : DHCPREQUEST on eth0 to 255.255.255.255 port 67
>>> 11:24:15 INFO     : DHCPACK from 192.168.84.254
>>> 11:24:15 INFO     : bound to 192.168.84.250 -- renewal in 3052
seconds.
>>> 11:24:15 INFO     : DHCPv4 eth0 - obtained lease 192.168.84.250
>>> 11:24:15 INFO     : DHCPv4 eth0 - option subnet-mask: 255.255.255.0
>>> 11:24:15 INFO     : DHCPv4 eth0 - option subnet-mask - prefix_len:
24
>>> broadcast: 192.168.84.254
>>> 11:24:15 INFO     : DHCPv4 eth0 - option routers:
>>> 11:24:15 ERROR : no DNS servers, can't look up hostname
>>>
>>> Thanks
>>>
>>> Brem

Try booting from a CentOS 5.4 LiveCD (or image).  If that does not get a
working DNS configuration through DHCP either, you will have a better
environment for tracking it down.  I'd suspect either firewall or
routing: if your VM really is getting 192.168.84.250 with default
gateway 192.168.84.254, can that gateway talk to the DNS server at
10.146.0.11? Is something on the way blocking the packets?  Or maybe the
DNS server does not respond to requests from that subnet.  If you have
access to the DNS server, check its logs, or run tcpdump to see if the
requests are arriving.  "ip addr list" and "ip route list" will show
your networking configuration, and should also work in the Anaconda
shell window on Alt-F2.  "cat /etc/resolv.conf" shows DNS configuration,
but I can't remember if that one works in Anaconda or not.


Moray.
"To err is human.  To purr, feline"






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