dns used for resolving mdns queries
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
nss-mdns (Ubuntu) |
New
|
Undecided
|
Unassigned |
Bug Description
Release:
root@lupus:
Description: Ubuntu 8.04.1
Release: 8.04
By default, this is included in /etc/nsswith.conf:
hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4
According to nss-mdns web page http://
"
The minimal versions will always deny to resolve host names that don't end in .local or addresses that aren't in the range 169.254.x.x (the range used by IPV4LL/
"
For some reason, normal DNS requests are still being made when a .local host is being resolved. When I run "getent hosts foo.local" and monitor the traffic using tshark, I get:
0.000000 10.65.17.20 -> 10.65.26.4 DNS Standard query AAAA foo.local
0.009858 10.65.26.4 -> 10.65.17.20 DNS Standard query response, No such name
0.009948 10.65.17.20 -> 10.65.26.4 DNS Standard query AAAA foo.local.bothi.fi
0.010132 10.65.26.4 -> 10.65.17.20 DNS Standard query response, No such name
0.111629 10.65.17.20 -> 224.0.0.251 MDNS Standard query A foo.local, "QM" question
1.114619 10.65.17.20 -> 224.0.0.251 MDNS Standard query A foo.local, "QM" question
3.118609 10.65.17.20 -> 224.0.0.251 MDNS Standard query A foo.local, "QM" question
7 packets captured
According to my understanding, those DNS Standard queries should not be there.
I get that, too, with "tcpdump -i eth0 proto UDP and port 53".
However, I'm not entirely sure whether this is a bug or a feature. Some people still run ".local" as an actual unicast LAN network name, and the current scheme makes sure that this continues to work as long as you don't have a real IPv4LL network. But indeed this would render the "[NOTFOUND=return]" quite useless.
Lennart, do you know a way to debug the particular modules, like mdns4_minimal and its return values?