Q. IXFR client behavior

[Nobumichi Ozoe]

Hi,

Now I'm trying to test Increment Zone Transfer (IXFR) using bind 9.3.2
as following enviroment. And I have a question about IXFR mechanizm on BIND9.

Q1. Why does an IXFR client make an IXFR query using TCP rather than UDP at first?

Q2. Why does an IXFR client ignore query response's SOA REFRESH time?
    An IXFR server set 180sec as REFRESH time, but an IXFR client sends query
    QTYPE=SOA every aroud 300sec.
    (I put capture file at http://www.tahi.org/~ozoe/dns/ixfr_inclement.pcap)

Network
-------

     IXFR client
        |192.168.0.10
--+-----+-----
  |
 IXFR server
   192.168.0.30

named.conf on IXFR server
-------------------
options {
        directory "/etc/namedb";
        provide-ixfr yes;
        ixfr-from-differences yes;
        notify no;
        dump-file "s/named_dump.db";
};

zone "sec.example.com" {
        type master;
        file "sec.example.com";
};


named.conf on IXFR client
--------------------------
options {
        directory "/etc/namedb";
        request-ixfr yes;
        notify no;
        dump-file "s/named_dump.db";
};

zone "sec.example.com" {
        type slave;
        masters {192.168.0.30;};
        file "s/sec.example.com";
};


sec.example.com zone file on IXFR server
-----------------------------------------

$TTL    86400; TTL of 30 sec
@       IN      SOA     NS7.sec.example.com. root.sec.example.com.  (
        1       ; Serial
        180     ; Refresh
        30      ; Retry
        360     ; Expire
        30      ; Minimum
)
        IN      NS      NS7.sec.example.com.
        IN      NS      NS1.sec.example.com.
        IN      MX      10      NS7
NS7     IN      A       192.168.0.31
        IN      AAAA    3ffe:501:ffff:100::31
NS1     IN      A       192.168.0.10
        IN      AAAA    3ffe:501:ffff:100::10
CL1     IN      A       192.168.0.20
CL2     IN      A       192.168.0.21

Updated zone information file on IXFR server
--------------------------------------------

$TTL    86400; TTL of 30 sec
@       IN      SOA     NS7.sec.example.com. root.sec.example.com.  (
        2       ; Serial
        180     ; Refresh
        30      ; Retry
        360     ; Expire
        30      ; Minimum
)
        IN      NS      NS7.sec.example.com.
        IN      NS      NS1.sec.example.com.
        IN      MX      10      NS7
NS7     IN      A       192.168.0.31
        IN      AAAA    3ffe:501:ffff:100::31
NS1     IN      A       192.168.0.10
        IN      AAAA    3ffe:501:ffff:100::10
CL1     IN      A       192.168.0.21
CL3     IN      A       192.168.0.22

-- 
Nobumichi Ozoe
IPv6 Business
Network & Software Development Dept.
Yokogawa Electric Corporation
E-mail: Nobumichi.Ozoe at jp.yokogawa.com
URL: http://www.yokogawa.com/