各位大大，望解惑

[root@izm5eb7o9hu1q8eoh3zi68z ~]# ifconfig

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500

        inet 172.31.153.255  netmask 255.255.240.0  broadcast 172.31.159.255

        ether 00:16:3e:05:25:9e  txqueuelen 1000  (Ethernet)

        RX packets 2171  bytes 271711 (265.3 KiB)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 1378  bytes 178314 (174.1 KiB)

        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

        loop  txqueuelen 1  (Local Loopback)

        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

[root@izm5eb7o9hu1q8eoh3zi68z ~]#

[root@izm5eb7o9hu1q8eoh3zi68z ~]# route -n

Kernel IP routing table

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

0.0.0.0         172.31.159.253  0.0.0.0         UG    0      0        0 eth0

169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 eth0

172.31.144.0    0.0.0.0         255.255.240.0   U     0      0        0 eth0

[root@izm5eb7o9hu1q8eoh3zi68z ~]#

[root@izm5eb7o9hu1q8eoh3zi68z ~]#

[root@izm5eb7o9hu1q8eoh3zi68z ~]#

[root@izm5eb7o9hu1q8eoh3zi68z ~]#

[root@izm5eb7o9hu1q8eoh3zi68z ~]#

[root@izm5eb7o9hu1q8eoh3zi68z ~]# traceroute -n 115.195.81.196

traceroute to 115.195.81.196 (115.195.81.196), 30 hops max, 60 byte packets

 1  * * *

 2  11.219.5.9  10.455 ms  10.519 ms 11.219.4.9  5.686 ms

 3  * * *

 4  11.219.68.34  0.426 ms  0.425 ms 11.219.68.50  0.413 ms

信息如上所示，网卡IP和网关IP不在同一网段，那进行外部访问的时候，数据走到网关172.31.159.253之前是不是还要经过在同一网段的交换机？或是通过其他方式连接至网关172.31.159.253？具体是什么逻辑呢