DNS queries with type=28 (AAAA, for IPV6)
For some time, my browser was refreshing pages very slowly, and after suggestions
from other members, I added entries into /etc/modprobe.conf.
After adding those entries in /etc/modprobe.conf,
the browsers refresh the pages very fast. The DNS queries are with type =1
(A, IPV4 address) and the response from nameserver is seen immediately.
However, there are some applications that still use IPV6 address in their
queries. I have configured evolution (as a POP3 mail client) to get emails
from gmail and here is the capture (from ethereal!)
15 31.33984 192.168.1.102 -> 192.168.1.1 DNS C pop.gmail.com. Internet AAAA ?
16 0.07952 192.168.1.1 -> 192.168.1.102 DNS R pop.gmail.com. Internet Addr 64.233.171.111
17 4.92045 192.168.1.102 -> 192.168.1.1 DNS C pop.gmail.com. Internet AAAA ?
18 0.09158 192.168.1.1 -> 192.168.1.102 DNS R pop.gmail.com. Internet Addr 64.233.171.111
19 4.90785 192.168.1.102 -> 192.168.1.1 DNS C pop.gmail.com.hsd1.ca.comcast.net. Internet AAAA ?
20 5.05421 192.168.1.102 -> 192.168.1.1 DNS C pop.gmail.com.hsd1.ca.comcast.net. Internet AAAA ?
21 5.01862 192.168.1.102 -> 192.168.1.1 DNS C pop.gmail.com. Internet Addr ?
22 0.09515 192.168.1.1 -> 192.168.1.102 DNS R pop.gmail.com. Internet Addr 64.233.171.111
If we look at the details of one packet (15 from above), we can see the query type is 28 (for
IPV6 address)
DNS: ----- DNS Header -----
DNS:
DNS: Query ID = 31116
DNS: Opcode: Query
DNS: RD (Recursion Desired)
DNS: 1 question(s)
DNS: Domain Name: pop.gmail.com.
DNS: Class: 1 (Internet)
DNS: Type: 28 (IPv6 Address) <------------ IPV6
DNS:
Mozilla for example sends the request correctly, as seen from this
DNS: ----- DNS Header -----
DNS:
DNS: Query ID = 38534
DNS: Opcode: Query
DNS: RD (Recursion Desired)
DNS: 1 question(s)
DNS: Domain Name: ads.rediff.com.
DNS: Class: 1 (Internet)
DNS: Type: 1 (Address)
DNS:
In spite of disabling IPV6 through modprobe.conf, why are some applications
still sending DNS queries with IPV6 address ? Even if it were to send those,
my name server seems to be responding right away and still the client
sends the query after another 5 seconds?
How do we circumvent this problem?
