Eu tenho um sistema isolado que não consegue acessar a Internet.
Eu quero usar um dos servidores para executar o servidor dhcp, e dar ip diferente em sub-rede diferente em que o cliente quer morar.
Eu posso enviar uma requisição para a subnet2 do cliente para o servidor, mas o servidor sempre retorna o ip na subnet1.
Abaixo está minha configuração.
subnet 172.16.50.0 netmask 255.255.255.0 {
range 172.16.50.100 172.16.50.200;
option subnet-mask 255.255.255.0;
option routers 172.16.50.254;
option broadcast-address 172.16.50.255;
option ip-forwarding off;
option domain-name-servers 8.8.8.8;
if exists user-class and option user-class = "iPXE" {
filename "bootstrap.ipxe";
} else {
filename "undionly.kpxe";
}
next-server 172.16.50.31;
}
subnet 172.16.51.0 netmask 255.255.255.0 {
range 172.16.51.100 172.16.51.200;
option subnet-mask 255.255.255.0;
option routers 172.16.51.254;
option broadcast-address 172.16.51.255;
option ip-forwarding off;
option domain-name-servers 8.8.8.8;
if exists user-class and option user-class = "iPXE" {
filename "bootstrap.ipxe";
} else {
filename "undionly.kpxe";
}
next-server 172.16.51.31;
}
$ sudo modprobe dummy
$ sudo ip link set name eth10 dev dummy0
$ sudo ip addr add 172.16.51.31/24 brd + dev eth10 label eth10:0
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp1s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 04:7d:7b:d8:bb:6a brd ff:ff:ff:ff:ff:ff
inet 172.16.50.31/24 brd 172.16.50.255 scope global enp1s0f0
valid_lft forever preferred_lft forever
inet6 fe80::67d:7bff:fed8:bb6a/64 scope link
valid_lft forever preferred_lft forever
3: enp1s0f1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN qlen 1000
link/ether 04:7d:7b:d8:bb:6b brd ff:ff:ff:ff:ff:ff
4: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
link/ether 52:54:00:36:03:d7 brd ff:ff:ff:ff:ff:ff
inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
valid_lft forever preferred_lft forever
5: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 500
link/ether 52:54:00:36:03:d7 brd ff:ff:ff:ff:ff:ff
7: eth10: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN
link/ether d2:b8:2e:44:a5:2f brd ff:ff:ff:ff:ff:ff
inet 172.16.51.31/24 brd 172.16.51.255 scope global eth10:0
valid_lft forever preferred_lft forever
enp1s0f0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 172.16.50.31 netmask 255.255.255.0 broadcast 172.16.50.255
inet6 fe80::67d:7bff:fed8:bb6a prefixlen 64 scopeid 0x20<link>
ether 04:7d:7b:d8:bb:6a txqueuelen 1000 (Ethernet)
RX packets 5288228 bytes 1902558434 (1.7 GiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 6310647 bytes 6023578728 (5.6 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device memory 0xdfe20000-dfe3ffff
enp1s0f1: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether 04:7d:7b:d8:bb:6b 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
device memory 0xdfe00000-dfe1ffff
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 0 (Local Loopback)
RX packets 6164718 bytes 2009821769 (1.8 GiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 6164718 bytes 2009821769 (1.8 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:36:03:d7 txqueuelen 0 (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
send dhcp-server-identifier 172.16.51.31;
$ dhclient -r -v ens20f0
Listening on LPF/ens20f0/54:ab:3a:3d:2c:7a
Sending on LPF/ens20f0/54:ab:3a:3d:2c:7a
Sending on Socket/fallback
DHCPRELEASE on ens20f0 to 172.16.50.31 port 67 (xid=0x41973da)
$ dhclient -s 172.16.51.31 -v ens20f0
Listening on LPF/ens20f0/54:ab:3a:3d:2c:7a
Sending on LPF/ens20f0/54:ab:3a:3d:2c:7a
Sending on Socket/fallback
DHCPDISCOVER on ens20f0 to 172.16.51.31 port 67 interval 7 (xid=0x2c4dfe6c)
DHCPREQUEST on ens20f0 to 172.16.51.31 port 67 (xid=0x2c4dfe6c)
DHCPOFFER from 172.16.50.31
DHCPPACK from 172.16.50.31 (xid=0x2c4dfe6c)
bound to 172.16.50.116 -- renewal in 20324 seconds.
Eu envio uma solicitação para 172.16.50.31. Mas eu só tenho o ip em 172.16.50.0/24.
Li uma solução on-line: link
Mas isso é no Ubuntu, não no centos. Eu não posso fazer isso passo a passo.
Existe algum método para fornecer ip na subnet differnet no CentOS 7?
Eu encontrei a solução sozinho.
Adicionar a interface virtual como interface permanente em / etc / sysconfig / network-script / permitirá que o servidor ofereça sub-redes múltiplas com uma interface real.
Se a interface for adicionada como temporária (ex. ifconfig eth0:1 172.16.52.0/24 ), o servidor não poderá atender com várias sub-redes.