Gentoo/Linuxでゲートウェイルータ作った時のメモ

OS: Gentoo/Linux

kernel: gentoo-sources-3.10.7

eth0: LAN側のNIC
eth1: WAN側のNIC


# emerge rp-pppoe

# cd /usr/src/linux

# make menuconfig

      Networking support --->
        Device Drivers
          [*]  Network device support
          <*> PPP (point-to-point protocol) support
            <*> PPP over Ethernet
            <*> PPP support for async serial ports
        Networking options --->
          [*]  IP: advanced router
          [*]  Network packet filtering framework (Netfilter) --->
            Core Netfilter Configuration --->
               {*}  Netfilter Xtables support (required for ip_tables)
              <M> "TCPMSS" target support
            IP: Netfilter Configuration  --->
              <M> IPv4 connection tracking support (required for NAT)
              <M> IP tables support (required for filtering/masq/NAT)
                <M> Packet filtering
                  <M> REJECT target support
                <M> Full NAT
                  <M> MASQUERADE target support
                  <M> REDIRECT target support


# emacs /etc/conf.d/net

config_ppp0="ppp"
link_ppp0="eth1"
plugins_ppp0="pppoe"
pppd_ppp0="
         defaultroute
         usepeerdns"
username_ppp0="user@example.com"
password_ppp0="pass"

# chmod 600 /etc/conf.d/net


# cd /etc/init.d
# ln -s net.lo net.ppp0
# rc-update add net.ppp0 default
# /etc/init.d/net.ppp0 start


# iptables -P INPUT ACCEPT
# iptables -P OUTPUT  ACCEPT
# iptables -P FORWARD ACCEPT

# iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu

# iptables -t nat -A POSTROUTING -j MASQUERADE

# /etc/init.d/iptables save

# /etc/init.d/iptables start

# rc-update add iptables default

# echo 1 > /proc/sys/net/ipv4/ip_forward

# for f in /proc/sys/net/ipv4/conf/*/rp_filter ; do echo 1 > $f ; done

# emacs /etc/sysctl.conf

net.ipv4.ip_forward = 1

net.ipv4.conf.default.rp_filter = 1

net.ipv4.ip_dynaddr = 1

多分これで動いた

特にiptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu

を設定しないとWebサイトによっては接続ができなくなる

参考

Linuxルーター構築(rp-pppoe+iptables) http://centossrv.com/linux-router.shtml

Home Router Guide http://www.gentoo.org/doc/en/home-router-howto.xml