Linux kernel 2.4 네트웍 트래픽 분산

   내부 네트웍                              +----------------+
 +------------+                             |     웹서버     |
 |   Net-A    |                             |(100.100.100.10)|
 |            |-+            리눅스 방화벽  +----------------+
 |192.168.1.x | |             커널 2.4.14           |        +--------------+
 +------------+ |          +---------------+        |        |              |
                |          |(100.100.100.2)|        |        |              |
 +------------+ | +------+ |           eth0|-----------------|              |  
 |   Net-B    | | | 내부 | |eth1           | (100.100.100.1) |              |
 |            |-+-|      |-|(192.168.1.254)|    E1 전용선    |    인터넷    |
 |192.168.2.x | | |라우터| |               |                 |              |
 +------------+ | +------+ |           ppp0|-----------------|              |
                |          |(200.200.200.2)|      ADSL       |              |
 +------------+ |          +---------------+ (200.200.200.1) |              |
 |   Net-C    | |                                            +--------------+
 |            |-+
 |192.168.3.x |
 +------------+

 General setup  --->
     [*] Networking support

 Networking options  --->
     <*> Packet socket
     [*]   Packet socket: mmapped IO
     [*] Kernel/User netlink socket
     [*]   Routing messages
     [*] Network packet filtering (replaces ipchains)
     [ ]   Network packet filtering debugging
     [*] Socket Filtering
     <*> Unix domain sockets
     [*] TCP/IP networking
     [*]   IP: advanced router
     [*]     IP: policy routing
     [*]       IP: use netfilter MARK value as routing key
     [*]       IP: fast network address translation
     [ ]     IP: equal cost multipath
     [*]     IP: use TOS value as routing key
     [*]     IP: verbose route monitoring
     [*]     IP: large routing tables

       IP: Netfilter Configuration  --->
           <M> Connection tracking (required for masq/NAT)
           <M>   FTP protocol support
           <M>   IRC protocol support
           <M> Userspace queueing via NETLINK (EXPERIMENTAL)
           <M> IP tables support (required for filtering/masq/NAT)
           <M>   limit match support
           <M>   MAC address match support
           <M>   netfilter MARK match support
           <M>   Multiple port match support
           <M>   TOS match support
           <M>   LENGTH match support
           <M>   TTL match support
           <M>   tcpmss match support
           <M>   Connection state match support
           <M>   Unclean match support (EXPERIMENTAL)
           <M>   Owner match support
           <M>   Packet filtering
           <M>     REJECT target support
           <M>   Full NAT
           <M>     MASQUERADE target support
           <M>   Packet mangling
           <M>     TOS target support
           <M>     MARK target support
           <M>   LOG target support
           <M>   TCPMSS target support

# ip route add default via 200.200.200.1 dev ppp0 table adslline metric 1
# ip route add default via 100.100.100.1 dev eth0 table adslline metric 2

# ip route add default via 200.200.200.1 dev ppp0 table main metric 2

#! /bin/sh

KERNELVER="`uname -r | cut -d. -f1,2`"

if [ "$KERNELVER" = "2.2" ]
then
    echo "This does not support the Kernel 2.2.x"
    exit 1
fi

IPTABLES=/sbin/iptables
IFCONFIG=/sbin/ifconfig
ECHO=/bin/echo
GREP=/bin/grep
AWK=/usr/bin/awk
SED=/bin/sed
IP=/sbin/ip
RTTAB=/etc/iproute2/rt_tables

ONLINEPPP0=`$IFCONFIG | $GREP ppp0 | $AWK '{print $1}'`

if [ -n "$ONLINEPPP0" ]
then
     $ECHO "PPP0 is ON-LINE...   Initializing routing table......"
else
     $ECHO "PPP0 is OFF-LINE..."
     exit 1
fi

# 내부 네트웍에 연결된 이더넷 카드
INTIF="eth1"

# 인터넷에 연결된 이더넷 카드
EXITIFETH="eth0"

#ppp 연결
EXITIFPPP0="ppp0"
ALLPPP="ppp+"

# eth1에 할당된 ip address
INTIP="`$IFCONFIG $INTIF | $GREP 'inet addr' | $AWK '{print $2}' | $SED -e 's/.*://'`"

# eth0에 할당된 ip address
FWIP="`$IFCONFIG $EXITIFETH | $GREP 'inet addr' | $AWK '{print $2}' | $SED -e 's/.*://'`"

# ppp0에 할당된 ip address
PPP0IP="`$IFCONFIG $EXITIFPPP0 | $GREP 'inet addr' | $AWK '{print $2}' | $SED -e 's/.*://'`"

# E1 전용선 게이트웨이
FWGW="100.100.100.1"

# ppp0 게이트웨이
PPP0GW="`$IFCONFIG $EXITIFPPP0 | $GREP 'inet addr' | $AWK '{print $3}' | $SED -e 's/.*://'`"

# 내부 네트웍 및 전용선 네트웍
NETA="192.168.1.0/24"
NETB="192.168.2.0/24"
NETC="192.168.3.0/24"
NETALL="192.168.0.0/16"
NETE1="100.100.100.0/24"
UNIVERSE="0.0.0.0/0"

add_rt_table() {
    # rt_tables 파일 생성
    $ECHO 255     local > $RTTAB
    $ECHO 254     main >> $RTTAB
    $ECHO 253     default >> $RTTAB
    $ECHO 0       unspec >> $RTTAB
    $ECHO 1       inr.ruhep >> $RTTAB

    # 사용할 라우팅 테이블 이름 삽입
    $ECHO 201 adslline >> $RTTAB

    # 라우팅 룰 추가
    $IP rule add from $NETC table adslline

    # 라우팅 테이블 생성
    $IP route add default via $PPP0GW dev $EXITIFPPP0 table adslline

    # 내부 네트웍과 E1 전용선 네트웍에 대한 라우팅을 local table에 추가
    $IP route add $NETE1 via $FWIP dev eth0 table local
    $IP route add $NETALL via $INTIP dev eth1 table local
}

del_rt_table() {
    # 라우팅 테이블과 룰 삭제
    $IP route del $NETALL via $INTIP dev $INTIF table local
    $IP route del $NETE1 via $FWIP dev $EXITIFETH table local
    $IP route del default via $PPP0GW dev $EXITIFPPP0 table adslline
    $IP rule del from $NETC table adslline
}

case "$1" in
    start)
        add_rt_table
        ;;
    stop)
        del_rt_table
        ;;
    restart)
        del_rt_table
        add_rt_table
        ;;
    *)
        echo "Usage: 스크립트 파일 이름 {start|stop|restart}"
        exit 1
        ;;
esac

exit 0