[FreeBSD 7.0-BETA1] strange behavior in hostname resolving order

Byung-Hee HWANG bh at izb.knu.ac.kr
Fri Nov 2 15:05:07 UTC 2007


To Whom It May Concern: (Cc'ed bind-users at isc.org)

Usually i prefer 6to4(stf(4)) to 6over4(gif(4)) because some 
tunnel providers like to limit bandwidth too musch. So until my 
upstream ISP give me native ipv6 addresses (it's take long time maybe), 
i'm going to use 6to4 instead of 6over4 continuous.

Here is my shot using 6to4:

bh at viola:~> uname -a
FreeBSD viola.izb.knu.ac.kr 7.0-BETA1 FreeBSD 7.0-BETA1 #0: 
Fri Nov  2 12:13:10 KST 2007     
root at viola.izb.knu.ac.kr:/usr/obj/usr/src/sys/GENERIC  i386

bh at viola:~> ifconfig rl0 | grep 2002
inet6 2002:9be6:9d5d:2:20b:6aff:fe56:969f prefixlen 64 autoconf 

bh at viola:~> ping6 -c 5 mx.jp.freebsd.org.
PING6(56=40+8+8 bytes) 
2002:9be6:9d5d:2:20b:6aff:fe56:969f --> 2001:218:422:1::15
16 bytes from 2001:218:422:1::15, icmp_seq=0 hlim=49 time=225.297 ms
16 bytes from 2001:218:422:1::15, icmp_seq=1 hlim=49 time=224.591 ms
16 bytes from 2001:218:422:1::15, icmp_seq=2 hlim=49 time=237.175 ms
16 bytes from 2001:218:422:1::15, icmp_seq=3 hlim=49 time=230.540 ms
16 bytes from 2001:218:422:1::15, icmp_seq=4 hlim=49 time=224.681 ms

--- mx.jp.freebsd.org ping6 statistics ---
5 packets transmitted, 5 packets received, 0.0% packet loss
round-trip min/avg/max/std-dev = 224.591/228.457/237.175/4.889 ms

bh at viola:~> traceroute6 mx.jp.freebsd.org.
traceroute6 to mx.jp.freebsd.org (2001:218:422:1::15) from 
2002:9be6:9d5d:2:20b:6aff:fe56:969f, 64 hops max, 12 byte packets
1  2002:9be6:9d5d:2:250:4dff:fe00:5df3  1.541 ms  0.949 ms  1.154 ms
[......]
23  v6.imgsrc.co.jp  264.635 ms  226.812 ms  232.207 ms
24  castle.jp.FreeBSD.org  427.683 ms  219.659 ms  222.862 ms
bh at viola:~> 

And from now on, i would give you one question. Why is 7.0-BETA1 
different from another -RELEASE in hostname resolving order? AFAIK, at 
least on 6.2-RELEASE, the order is first IPv6 and then IPv4. However, 
7.0-BETA1 try to lookup in first IPv4 than IPv6. Here is the evidence:

        bh at setaria:~> uname -srm
        FreeBSD 6.2-RELEASE-p8 i386
        bh at setaria:~> telnet mx.jp.freebsd.org 25
        Trying 2001:218:422:1::15...
        Connected to mx.jp.freebsd.org.
        Escape character is '^]'.
        [......]
        bh at setaria:~> ssh -v mx.jp.freebsd.org.
        debug1: Connecting to mx.jp.freebsd.org. [2001:218:422:1::15]
        ^C
        
And

        bh at viola:~> uname -srm
        FreeBSD 7.0-BETA1 i386
        bh at viola:~> telnet mx.jp.freebsd.org 25
        Trying 210.226.20.15...
        Connected to mx.jp.freebsd.org.
        Escape character is '^]'.
        [......]
        bh at viola:~> ssh -v mx.jp.freebsd.org.
        debug1: Connecting to mx.jp.freebsd.org. [210.226.20.15]
        ^C

What happended? Is there anyone to dislike IPv6 in src committers?
Please let me know the correct answer to this puzzle ;;

Byung-Hee

-- 
"After super, can you drive me and the kids to New York in your car?"
"That's what I came for."
		-- Kay Adams and Tom Hagen, "Chapter 32", page 443




More information about the bind-users mailing list