[FreeBSD] latence connexion SSH

Bonjour,

Voici ma configuration :
Portable Compaq LTE5250 (120MHz, 32Mo, 2Go DD),
carte Xircom (REM56G-100)
modem RNIS externe (Djinn Internet Numéris)
FreeBSD 4.8
Ipfw2 activé

Quand je lance une connexion SSH à partir d'une machine du LAN, le temps de
latence entre l'envoie de la commande et la demande du mot de passe dépasse
la minute.

La version sans ipfw fonctionne sans ce délai.

Voici le contenu de /etc/firewall/fwrules
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fwcmd="/sbin/ipfw"

# Force a flushing of the current rules before we reload.
$fwcmd -f flush

# Divert all packets through the tunnel interface.
$fwcmd add divert natd all from any to any via tun0

# Allow all connections that have dynamic rules built for them,
# but deny established connections that don't have a dynamic rule.
$fwcmd add check-state
$fwcmd add deny tcp from any to any established

# Allow all localhost connections
$fwcmd add allow tcp from me to any out via lo0 setup keep-state
$fwcmd add deny tcp from me to any out via lo0
$fwcmd add allow ip from me to any out via lo0 keep-state

# Allow all connections from my network card that I initiate
$fwcmd add allow tcp from me to any out xmit any setup keep-state
$fwcmd add deny tcp from me to any
$fwcmd add allow ip from me to any out xmit any keep-state

# Everyone on the Internet is allowed to connect to the following
# services on the machine. This example specifically allows connections
# to sshd.
$fwcmd add allow tcp from any to me dst-port 22 in recv any setup keep-state

# This sends a RESET to all ident packets.
$fwcmd add reset log tcp from any to me 113 in recv any

# Enable ICMP: remove type 8 if you don't want your host to be pingable
$fwcmd add allow icmp from any to any icmptypes 0,3,8,11,12,13,14

# Deny all the rest.
$fwcmd add deny log ip from any to any
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Une idée ?
merci.
--
CTS