Securing-Optimizing-RH-Linux-1_2_116
Comments and suggestions concerning this book should be mailed to gmourani@videotron.ca
© Copyright 1999-2000 Gerhard Mourani and Open Network Architecture ®
116
# -----------------
# Reject, rather than deny, the incoming auth port. (NET-3-HOWTO)
ipchains -A input -i $EXTERNAL_INTERFACE -p tcp \
-s $ANYWHERE \
-d $IPADDR 113 -j REJECT
# ------------------------------------------------------------------
# SMTP client (25)
# ----------------
ipchains -A input -i $EXTERNAL_INTERFACE -p tcp ! -y \
-s $SMTP_SERVER 25 \
-d $IPADDR $UNPRIVPORTS -j ACCEPT
ipchains -A output -i $EXTERNAL_INTERFACE -p tcp \
-s $IPADDR $UNPRIVPORTS \
-d $SMTP_SERVER 25 -j ACCEPT
# ------------------------------------------------------------------
# FTP server (20, 21)
# -------------------
# incoming request
ipchains -A input -i $EXTERNAL_INTERFACE -p tcp \
-s $ANYWHERE $UNPRIVPORTS \
-d $IPADDR 21 -j ACCEPT
ipchains -A output -i $EXTERNAL_INTERFACE -p tcp ! -y \
-s $IPADDR 21 \
-d $ANYWHERE $UNPRIVPORTS -j ACCEPT
# PORT MODE data channel responses
#
ipchains -A input -i $EXTERNAL_INTERFACE -p tcp ! -y \
-s $ANYWHERE $UNPRIVPORTS \
-d $IPADDR 20 -j ACCEPT
ipchains -A output -i $EXTERNAL_INTERFACE -p tcp \
-s $IPADDR 20 \
-d $ANYWHERE $UNPRIVPORTS -j ACCEPT
# PASSIVE MODE data channel responses
ipchains -A input -i $EXTERNAL_INTERFACE -p tcp \
-s $ANYWHERE $UNPRIVPORTS \
-d $IPADDR $UNPRIVPORTS -j ACCEPT
ipchains -A output -i $EXTERNAL_INTERFACE -p tcp ! -y \
-s $IPADDR $UNPRIVPORTS \
-d $ANYWHERE $UNPRIVPORTS -j ACCEPT
# ------------------------------------------------------------------
# OUTGOING TRACEROUTE
# -------------------
ipchains -A output -i $EXTERNAL_INTERFACE -p udp \
-s $IPADDR $TRACEROUTE_SRC_PORTS \
-d $ANYWHERE $TRACEROUTE_DEST_PORTS -j ACCEPT