概括
我目前正在使用 Debian Wheezy 上的 Shorewall 4.5.5.3 开发一个三接口软件防火墙，我在 loc (eth2) 和 dmz (eth1) 接口方面遇到了一些困难。fw (eth0) 接口似乎工作正常，但我无法 ping loc 或 dmz 区域上的 PC。网络中的 /etc/network/interfaces 设置可能有问题。
fw 接口通过我的 ISP 在 dhcp 上运行，我为 loc 和 dmz 接口以及这些区域内的 PC 配置了静态 IP。我尝试使用的配置是三接口和单 IP 配置。参考文档位于 Shorewall 网站上，“三接口防火墙“。我不知道如何处理 eth1 或 eth2 接口上的网关，因为 Shorewall 文档没有解释这一点。我假设它将是与 eth0 相同的网关，但我不知道如何做到这一点，因为 eth0 在 dhcp 上。
联网
固件节点的 /etc/network/interfaces：
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto eth0
iface eth0 inet dhcp
# Secondary network interface for dmz
auto eth1
iface eth1 inet static
address 10.10.1.1/24
netmask 255.255.255.0
# Tirtirary network interface for loc
auto eth2
iface eth2 inet static
address 10.10.2.1/24
netmask 255.255.255.0
dmz 的 /etc/network/interfaces
# dmz network interface
auto eth0
iface eth0 inet static
address 10.10.1.2/24
netmask 255.255.255.0
gateway 10.10.1.1
从 dmz 开始，我的网络接口设置有问题吗？
当我重新启动网络时发生的情况如下：
Listening on LPF/eth0/HEX:...:...
Sending on LPF/eth0/HEX:...:...
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 6
DHCPREQUEST on eth0 to 255.255.255.255 port 67
DHCPOFFER from XY.IP...
DHCPACK from XY.IP...
suspect value in ^1/7078C526/res-5000-2.0 option - discarded
suspect value in ^1/FBEA1017/res-5000-2.0 option - discarded
bound to NEW.IP... -- renewal in 33594 seconds.
done.
我不明白“可疑.... - 已丢弃”这句话的意思。这是否表示存在问题，或者这些潜在 IP 是否被拒绝了？
这些是 ifconfig 的结果：
eth0 Link encap:Ethernet HWaddr MAC
inet addr:DHCP.IP Bcast:DHCP.BC Mask:DHCP.M
inet6 addr: inet6.IP Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:268607 errors:0 dropped:0 overruns:0 frame:0
TX packets:89830 errors:0 dropped:0 overruns:0 carrier:7
collisions:0 txqueuelen:1000
RX bytes:25066229 (23.9 MiB) TX bytes:10734393 (10.2 MiB)
Interrupt:17
eth1 Link encap:Ethernet HWaddr c0:4a:00:03:00:04
inet addr:10.10.1.1 Bcast:10.10.1.255 Mask:255.255.255.0
inet6 addr: fe80::c24a:ff:fe03:4/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:82 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:4664 (4.5 KiB)
Interrupt:19 Base address:0xac00
eth2 Link encap:Ethernet HWaddr c0:4a:00:07:6a:31
inet addr:10.10.2.1 Bcast:10.10.2.255 Mask:255.255.255.0
inet6 addr: fe80::c24a:ff:fe07:6a31/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:48 errors:0 dropped:0 overruns:0 frame:0
TX packets:33 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2880 (2.8 KiB) TX bytes:2578 (2.5 KiB)
Interrupt:16 Base address:0xe800
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:41 errors:0 dropped:0 overruns:0 frame:0
TX packets:41 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:4592 (4.4 KiB) TX bytes:4592 (4.4 KiB)
Shorewall 设置
接口
net eth0 tcpflags,dhcp,nosmurfs,routefilter,logmartians,sourceroute=0
dmz eth1 tcpflags,nosmurfs,routefilter,logmartians
loc eth2 tcpflags,nosmurfs,routefilter,logmartians
面具
eth0 10.10.1.0/24
eth0 10.10.2.0/24
参数
ETH0_IP=$(find_first_interface_address eth0)
政策
loc net ACCEPT
net all DROP info
# THE FOLLOWING POLICY MUST BE LAST
all all REJECT info
路线停止
eth1 -
eth2 -
规则
SECTION NEW
# Don't allow connection pickup from the net
Invalid(DROP) net all
# Accept DNS connections from the firewall to the Internet
DNS(ACCEPT) $FW net
# Accept SSH connections from the local network to the firewall and DMZ
SSH(ACCEPT) loc $FW
SSH(ACCEPT) loc dmz
# DMZ DNS access to the Internet
DNS(ACCEPT) dmz net
# Drop Ping from the "bad" net zone.
Ping(DROP) net $FW
# Make ping work bi-directionally between the dmz, net, Firewall and local zone
# (assumes that the loc-> net policy is ACCEPT).
Ping(ACCEPT) loc $FW
Ping(ACCEPT) dmz $FW
Ping(ACCEPT) loc dmz
Ping(ACCEPT) dmz loc
Ping(ACCEPT) dmz net
Ping(ACCEPT) loc net
ACCEPT $FW net icmp
ACCEPT $FW loc icmp
ACCEPT $FW dmz icmp
# Allow connection to web server from loc to dmz
DNAT loc dmz:10.10.1.2 tcp - 80,443 $ETH0_IP
# Allow DNS connection to internal server from net
DNS(ACCEPT) loc dmz:10.10.1.3
DNS(ACCEPT) $FW dmz:10.10.1.3
DNS(ACCEPT) loc dmz:10.10.1.4
DNS(ACCEPT) $FW dmz:10.10.1.4
# Allow SMTPS traffic to internal server from net
SMTPS(ACCEPT) dmz:10.10.1.2 $FW
POP3S(ACCEPT) $FW dmz:10.10.1.2
# Allow SSH and SFTP on web server
SSH(ACCEPT) $FW dmz:10.10.1.2
SSH(ACCEPT) net $FW
岸墙配置文件
# Only change in this file:
IP_FORWARDING=On
区域
fw firewall
net ipv4
loc ipv4
dmz ipv4
岸墙检查
Checking...
Processing /etc/shorewall/params ...
Processing /etc/shorewall/shorewall.conf...
Loading Modules...
Checking /etc/shorewall/zones...
Checking /etc/shorewall/interfaces...
Determining Hosts in Zones...
Locating Action Files...
Checking /usr/share/shorewall/action.Drop for chain Drop...
Checking /usr/share/shorewall/action.Broadcast for chain Broadcast...
Checking /usr/share/shorewall/action.Invalid for chain Invalid...
Checking /usr/share/shorewall/action.NotSyn for chain NotSyn...
Checking /usr/share/shorewall/action.Reject for chain Reject...
Checking /etc/shorewall/policy...
Adding Anti-smurf Rules
Adding rules for DHCP
Checking TCP Flags filtering...
Checking Kernel Route Filtering...
Checking Martian Logging...
Checking Accept Source Routing...
Checking /etc/shorewall/masq...
Checking MAC Filtration -- Phase 1...
Checking /etc/shorewall/rules...
Checking /usr/share/shorewall/action.Invalid for chain %Invalid...
Checking MAC Filtration -- Phase 2...
Applying Policies...
Checking /etc/shorewall/routestopped...
Shorewall configuration verified
岸墙开始
Compiling...
Processing /etc/shorewall/params ...
Processing /etc/shorewall/shorewall.conf...
Loading Modules...
Compiling /etc/shorewall/zones...
Compiling /etc/shorewall/interfaces...
Determining Hosts in Zones...
Locating Action Files...
Compiling /usr/share/shorewall/action.Drop for chain Drop...
Compiling /usr/share/shorewall/action.Broadcast for chain Broadcast...
Compiling /usr/share/shorewall/action.Invalid for chain Invalid...
Compiling /usr/share/shorewall/action.NotSyn for chain NotSyn...
Compiling /usr/share/shorewall/action.Reject for chain Reject...
Compiling /etc/shorewall/policy...
Adding Anti-smurf Rules
Adding rules for DHCP
Compiling TCP Flags filtering...
Compiling Kernel Route Filtering...
Compiling Martian Logging...
Compiling Accept Source Routing...
Compiling /etc/shorewall/masq...
Compiling MAC Filtration -- Phase 1...
Compiling /etc/shorewall/rules...
Compiling /usr/share/shorewall/action.Invalid for chain %Invalid...
Compiling MAC Filtration -- Phase 2...
Applying Policies...
Generating Rule Matrix...
Creating iptables-restore input...
Compiling /etc/shorewall/routestopped...
Shorewall configuration compiled to /var/lib/shorewall/.start
Starting Shorewall....
Initializing...
Setting up Route Filtering...
Setting up Martian Logging...
Setting up Accept Source Routing...
Setting up Traffic Control...
Preparing iptables-restore input...
Running /sbin/iptables-restore...
IPv4 Forwarding Enabled
done.
平
在 fw 终端：ping 10.10.1.2
PING 10.10.1.2 (10.10.1.2) 56(84) bytes of data.
From 10.10.1.1 icmp_seq=1 Destination Host Unreachable
From 10.10.1.1 icmp_seq=2 Destination Host Unreachable
From 10.10.1.1 icmp_seq=3 Destination Host Unreachable
在 dmz 终端：ping 10.10.1.1
connect: network not reachable
我不知道哪里缺失/错误。如能提供任何帮助我将不胜感激。
答案1
解决方案
我找到了问题的答案，那就是 dmz 上的网络配置。dmz 位于 Dell Power Edge 1950 上，我在其中运行 10.10.1.2/24 上的硬件节点和 OpenVZ 的虚拟节点 venet0。我当时并不关心连接到 OpenVZ 节点，但甚至无法连接到硬件节点。修改网络信息并删除 CIDR 添加的 /24 后，一切都变得井然有序。我在硬件节点上运行 CentOS 6.5，我猜它不喜欢 CIDR 寻址。
我现在正在从 fw ping dmz，因此网关是打开的，快乐的日子：
> ping 10.10.2.1
PING 10.10.2.1 (10.10.2.1) 56(84) bytes of data.
64 bytes from 10.10.2.1: icmp_req=1 ttl=64 time=0.056 ms
64 bytes from 10.10.2.1: icmp_req=2 ttl=64 time=0.027 ms
64 bytes from 10.10.2.1: icmp_req=3 ttl=64 time=0.026 ms
64 bytes from 10.10.2.1: icmp_req=4 ttl=64 time=0.025 ms
概括
配置很可靠，所以我希望它能帮助其他人设置 Shorewall 接口。