我有一台 vpn 服务器（服务器 A）。服务器 A 连接到另一台 vpn 服务器（服务器 B）。服务器 A 有一些客户端。
是否可以仅将来自服务器 A 的 vpn 客户端的流量路由到服务器 B 的连接，以便机器 A 将使用默认互联网连接？
每个客户端都连接到某个 ppp+ 接口（ppp1-10），其 IP 地址为 11.0.0.1-10。11.0.1.1 - pptpd 服务器的 IP。Ppp0 是连接到服务器 B 的接口。
ifconfig 输出：
eth0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether e8:03:9a:93:07:53 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 13486316 bytes 3242965197 (3.0 GiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 13486316 bytes 3242965197 (3.0 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ppp0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1400
inet 192.168.1.50 netmask 255.255.255.255 destination 192.168.1.1
ppp txqueuelen 3 (Point-to-Point Protocol)
RX packets 12 bytes 949 (949.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 12 bytes 1411 (1.3 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ppp1: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1396
inet 11.0.1.1 netmask 255.255.255.255 destination 11.0.0.1
ppp txqueuelen 3 (Point-to-Point Protocol)
RX packets 7 bytes 88 (88.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 7 bytes 82 (82.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.4 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::9244:b58:9664:49b3 prefixlen 64 scopeid 0x20<link>
ether b8:03:05:4f:8a:44 txqueuelen 1000 (Ethernet)
RX packets 3950317 bytes 2674081227 (2.4 GiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 9771716 bytes 2046374004 (1.9 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
路线-n输出：
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 0.0.0.0 0.0.0.0 U 50 0 0 ppp0
0.0.0.0 192.168.1.1 0.0.0.0 UG 600 0 0 wlan0
11.0.0.1 0.0.0.0 255.255.255.255 UH 0 0 0 ppp1
"ip of server B" 192.168.1.1 255.255.255.255 UGH 0 0 0 wlan0
"ip of server B" 192.168.1.1 255.255.255.255 UGH 600 0 0 wlan0
192.168.1.0 0.0.0.0 255.255.255.0 U 600 0 0 wlan0
192.168.1.1 0.0.0.0 255.255.255.255 UH 50 0 0 ppp0
192.168.1.1 0.0.0.0 255.255.255.255 UH 600 0 0 wlan0