Red Hat Bugzilla – Bug 176615
dhcpd omits domainname when sending dynamic dns update
Last modified: 2007-11-30 17:11:19 EST
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Description of problem:
between dhcp-3.0.2-22 and dhcp-3.0.2-24 some code was moved around and i think this had an undesired side-effect. i tried to find the exact spot, but couldn't find it.
The release notes say:
>"append"ing a string onto the end of a "t" type option (such as the
>domain-name field) that had been improperly NULL-terminated by the
>DHCP server will no longer result in a truncated string containing
>only the option from the server, and not the expected appended value.
For me it has the opposite effect.
See the attached logfile.
Notice how 3.0.2-24 says only BOOLE while 3.0.2-22 says BOOLE.creaholic.com.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. set up a dhcp-server for dynamic dns updates
2. have a nt-client
3. in a dos-shell release ip ("ipconfig /release")
4. in a dos-shell renew ip ("ipconfig /renew")
Actual Results: logfile on dhcp-server shows error:
Unable to add forward map from BOOLE to 192.168.131.226: timed out
zonefiles on dns-server has no records for BOOLE
Expected Results: logfile should show:
Added new forward map from BOOLE.creaholic.com. to 192.168.131.226
added reverse map from 18.104.22.168.in-addr.arpa. to BOOLE.creaholic.com.
zonefiles on dns-server should have forward and reverse records for BOOLE
notice in attached logfile how it uses the fqdn to remove the dns-records, but uses the hostname without domainname to add dns-records.
Created attachment 122601 [details]
logfile showing good and bad behaviour
I'm investigating this now.
Did you try the latest dhcp-3.0.2-28.FC4 release now in updates/testing
(and being moved to updates/final today) ? This release has the complete
upstream patch for the null termination issue.
It would also be most helpful if you could gather a tcpdump of the server/client
traffic on the server:
# tcpdump -nl -i any -vvv -s 4096 -X port bootps or port bootpc \
Then boot the client, duplicating the problem, 'pkill tcpdump', and append
the /tmp/dhcp.tcpdump.log contents to this bug report - thank you.
I cannot reproduce this issue with dhcp-3.0.2-28.FC4, or with dhcp-3.0.1-52.EL4
in RHEL-4, both of which have the latest upstream fix for the trailing NUL
I was using a Windows-XP-Professional client, which had the option
"Register this connection's addresses in DNS" checked (selected) in the
"DNS" tab of the "Advanced TCP/IP Settings" dialog, reached by clicking on
the "Advanced" button of the "Internet Protocol (TCP/IP) Properties" dialog
of the "Local Area Connection Properties" dialog.
NOTE: Windows has several options regarding DDNS updates :
o "Append primary and connection specific DNS suffixes" -
The "connection specific DNS suffix" comes from the DHCP 'domain-name'
option, and is listed in the 'ipconfig' output.
The "primary" suffix is the suffix of the primary DNS server (which may
or may not be in the DHCP 'domain-name-servers' option).
o "Append these DNS suffixes" -
A list of domain name suffixes to update can be specified explicitly.
o "DNS suffix for this connection" -
A DNS suffix can be explicitly specified for the connection.
Note also that the dhcp server can request the client to do the DNS updates
by sending the a 'fqdn.server-update' value of 0 (false) ( or by setting the
'allow client-updates' option ) (but I'm not sure how you'd tell windows about
the DNS zone keys).
If you still have problems with dhcp-3.0.2-28.FC4, please gather the tcpdump
output requested above, and send me it along with your dhcpd.conf file -
Can you reproduce this problem with dhcp-3.0.2-28.FC4 ? I've not been able to.
If you can, please send me the tcpdump and dhcpd.conf data requested above,
and re-open this bug - thank you.
Created attachment 123200 [details]
tcpdump of dhcp client/server communication
Created attachment 123201 [details]
Problem still persists with dhcp-3.0.2-28.FC4.
-dhcp-client ist windows nt (not xp)
-dhcp-server is set to do the ddns-update.
-the dhcp-client doesn't know anything about ddns.
Created attachment 123202 [details]
tcpdump of dhcp-server to dns-server traffic
note how dhcpd sends only TAYLOR not taylor.creaholic.com to the dns.
Many thanks for appending the client->server dhcp traffic - I've found and
fixed the problem now.
This bug is fixed with dhcp-3.0.2-30.FC4, to be release to FC-4/Updates/Testing
today, and dhcp-3.0.3-20.FC5 in Rawhide.
Please try out the new version and let me know of any issues - thanks .
From User-Agent: XML-RPC
dhcp-3.0.2-30.FC4 has been pushed for FC4, which should resolve this issue. If these problems are still present in this version, then please make note of it in this bug report.
we tested dhcp-3.0.2-30.FC4 and it seems to work fine.
thanks a lot for fixing it!