현 네트워크의 Gateyway 알아내기
route 명령은 Kernel 버전에 따라 정보를 제대로 보여주지 못함.
버전에 관계 없이, "netstat -rn" 또는 "ip route"를 통해 확인이 가능함
RHEL 7.5
# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 192.171.6.1 0.0.0.0 UG 0 0 0 eno1
192.171.6.0 0.0.0.0 255.255.254.0 U 0 0 0 eno1
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eno1
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default gateway 0.0.0.0 UG 0 0 0 eno1
192.171.6.0 0.0.0.0 255.255.254.0 U 0 0 0 eno1
link-local 0.0.0.0 255.255.0.0 U 1002 0 0 eno1
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
# ip route
default via 192.171.6.1 dev eno1
192.171.6.0/23 dev eno1 proto kernel scope link src 192.171.6.28
169.254.0.0/16 dev eno1 scope link metric 1002
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1
RHEL 6.7
# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.54.72.0 * 255.255.248.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 1002 0 0 eth0
default 10.54.79.254 0.0.0.0 UG 0 0 0 eth0
# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.54.72.0 0.0.0.0 255.255.248.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
0.0.0.0 192.54.79.254 0.0.0.0 UG 0 0 0 eth0
# ip route
192.54.72.0/21 dev eth0 proto kernel scope link src 192.54.72.112
169.254.0.0/16 dev eth0 scope link metric 1002
default via 192.54.79.254 dev eth0