sshd. "UseDNS no" ignored?

[Stanislaw Halik]

On Tue, Nov 21, 2006, Cristiano Deana wrote:
> # uname -a
> FreeBSD circe.cmp 6.2-PRERELEASE FreeBSD 6.2-PRERELEASE #0: Wed Nov 15
> 16:13:14 CET 2006     root at circe.cmp:/usr/obj/usr/src/sys/PAECMP  i386
> # grep UseDNS /etc/ssh/sshd_config
> UseDNS no
> # /etc/rc.d/sshd restart
> Stopping sshd.
> Starting sshd.

> now, start a ssh session from a client (192.168.7.8). my sshd machine
> is 192.168.18.3 and 192.168.18.251is the dns.

> # tcpdump -ni bce0 port 53
> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> listening on bce0, link-type EN10MB (Ethernet), capture size 96 bytes
> 11:07:52.069663 IP 192.168.18.3.60321 > 192.168.18.251.53:  48923+
> PTR? 8.7.168.192.in-addr.arpa. (42)
[snip]

A wild guess: tcpwrappers are enabled, perhaps?