IPv6 problem of an IPv4 user
I apologize for posting this on a developer list, but so far I did
not get any useful clues from the user list or from Usenet.
I have a home network which contains 2 linux boxes. One is the
gateway/firewall (2 NIC's, one for the LAN, one for the ADSL
modem). The ADSL line is of the pptp type.
The gateway has no keyboard or monitor; so I telnet into it from
the other machine if I want to change anything. The telnet daemon
on the gateway only listens to the home network, not to the
outside world (I use xinetd).
The system has no name server. I rely on /etc/hosts files and (for
outside addresses) the ISP's name servers in /etc/resolv.conf.
However, something is seriously wrong with name resolution on my
system, as I recently discovered when I started to play with tcpdump.
(Note -- on the gateway machine, I can see what happens on the
outside line by means of (telnet to gateway, then)
tcpdump -i ppp0.
-- on the other machine, I can see what happens on the LAN
by just tcpdump.)
So when I recently looked at the traffic on the LAN, I saw that
when I did a telnet to the gateway, a DNS request was sent to the
ISP's nameservers. I other words, the outside world got involved
with something strictly local. I hardly know anything about DNS,
but I noticed that the tcpdump output had "AAAA" in it, meaning
(as far as I know) a request for an IPv6 address.
The local (IPv4 of course) address of the gateway is 192.168.1.2.
When I did a telnet to its numerical address (instead of its name)
no DNS traffic appeared on the LAN.
I also found that when instead of
telnet <gatewaymachinename>
I called
telnet -4 <gatewaymachinename>
no DNS traffic appeared *on the LAN*. The -4 option on telnet
means "force IPv4 address resolution". So I thought I had solved
it. In fact I announced this proudly on the user list...
But I haven't solved it. Telnetting to the gateway still generates
"AAAA" type DNS requests to the outside world -- on the ADSL line.
And what's more, these requests are generated even if I specify
the gateway's numerical address instead of its name.
The only thing I can think of is that in.telnetd on the gateway
does this. But how do I stop it?
System information: both systems Debian Woody. Both systems have
*no* support for IPv6 compiled in the kernel (at the moment I have
no use whatever for IPv6).
Enlightenment would be much appreciated. Solutions should
preferably not involve installing a nameserver...
Regards, Jan
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