I am using a router/switch Cisco C1111-8p with IOS XE 16.8
.
I have 3 VLANs:
- 1: native/management
- 20: dev
- 50: Guests
I'd like to block Guests/VLAN50 to communicate with anybody else but Internet.
For that, I created an access-list standard with the subnet of the VLAN50. And I apply this ACL to the SVI of VLAN1/native/management and VLAN20/dev outbound (point of view of the router).
conf t
access-list 10 deny 192.168.50.0 0.0.0.255
access-list 10 permit any
end
# VLAN 1 DEFAULT NATIVE
conf t
vlan 1
interface vlan 1
ip address 192.168.0.1 255.255.255.0
ip nat inside
ip access-group 10 out
end
# VLAN 20
conf t
vlan 20
name Dev
interface vlan 20
ip address 192.168.20.1 255.255.255.0
ip nat inside
ip access-group 10 out
end
Ping of a device connected to the VLAN1 native is filtered:
$ ping 192.168.0.200
PING 192.168.0.200 (192.168.0.200) 56(84) bytes of data.
From 192.168.50.1 icmp_seq=1 Packet filtered
From 192.168.50.1 icmp_seq=2 Packet filtered
From 192.168.50.1 icmp_seq=3 Packet filtered
Nevertheless, I still can ping the VLAN1 and VLAN20 gateway 192.168.0.1
and 192.168.20.1
.
$ ping 192.168.0.1
PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data.
64 bytes from 192.168.0.1: icmp_seq=1 ttl=255 time=17.9 ms
64 bytes from 192.168.0.1: icmp_seq=2 ttl=255 time=30.4 ms
$ ping 192.168.20.1
PING 192.168.20.1 (192.168.20.1) 56(84) bytes of data.
64 bytes from 192.168.20.1: icmp_seq=1 ttl=255 time=2.73 ms
64 bytes from 192.168.20.1: icmp_seq=2 ttl=255 time=23.7 ms
Why?
I'm using a Wireless Access Point to make my test with a SSID for each different VLAN and VLAN1 as native VLAN. I'd like to first test with an ACL standard before using extended.
Full config for reference (I don't write the DHCP part):
vlan internal allocation policy ascending
!
!
!
!
!
!
interface Loopback0
ip address 1.1.1.1 255.255.255.255
!
interface GigabitEthernet0/0/0
description WAN
ip address x.x.x.x 255.255.255.252
ip nat outside
negotiation auto
!
interface GigabitEthernet0/0/1
no ip address
shutdown
negotiation auto
!
interface GigabitEthernet0/1/0
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet0/1/1
shutdown
!
interface GigabitEthernet0/1/2
switchport access vlan 10
switchport mode access
!
interface GigabitEthernet0/1/3
switchport access vlan 20
switchport mode access
!
interface GigabitEthernet0/1/4
shutdown
!
interface GigabitEthernet0/1/5
shutdown
!
interface GigabitEthernet0/1/6
switchport mode access
!
interface GigabitEthernet0/1/7
switchport mode access
!
interface Vlan1
ip address 192.168.0.1 255.255.255.0
ip nat inside
ip access-group 10 in
!
interface Vlan10
ip address 192.168.10.1 255.255.255.0
ip nat inside
ip access-group 10 out
!
interface Vlan20
ip address 192.168.20.1 255.255.255.0
ip nat inside
ip access-group 10 out
!
interface Vlan50
ip address 192.168.50.1 255.255.255.0
ip nat inside
!
ip nat inside source list NAT interface GigabitEthernet0/0/0 overload
ip forward-protocol nd
no ip http server
ip http secure-server
ip dns server
ip route 0.0.0.0 0.0.0.0 x.x.x.x
!
!
ip access-list standard NAT
permit 192.168.10.0 0.0.0.255
permit 192.168.0.0 0.0.0.255
permit 192.168.20.0 0.0.0.255
permit 192.168.50.0 0.0.0.255
!
access-list 10 deny 192.168.50.0 0.0.0.255
access-list 10 permit any
!
!
!
!
control-plane
!
!
line con 0
transport input none
stopbits 1
line vty 0 4
login local
transport input ssh
!
wsma agent exec
!
wsma agent config
!
wsma agent filesys
!
wsma agent notify
!
!
end
ip access-group 10 in
in
, I can ping not only the gateway but also devices. It needs to be outbound applied to each other VLANs.