07-12-2023 07:25 AM
I am trying to lock down some VLANs on a Cisco Cataylst 3850 with IOS XE 16.12.9 Gibraltar
I need vlan 101 to talk to 102 and 103 and get out to the internet
I need 103 to only talk to 101 and 102 with no internet
I tried to apply this ACL to 103 but can still ping everything
ip access-list extended 103 permit ip any 192.168.101.0 0.0.0.255 permit ip any 192.168.102.0 0.0.0.255 deny ip any any interface vlan 103 ip access group 103 in
07-12-2023 08:21 AM
ip access-list extended 103 permit ip any 192.168.101.0 0.0.0.255 permit ip any 192.168.102.0 0.0.0.255 deny ip any any interface vlan 103 ip access group 103 OUT
07-12-2023 08:27 AM
hello @RaymondBui97693,
ip access-list extended 101
permit ip any any
ip access-list extended 103
permit ip 192.168.101.0 0.0.0.255 any
permit ip 192.168.102.0 0.0.0.255 any
deny ip any any
interface Vlan101
ip access-group 101 in
interface Vlan103
ip access-group 103 in
With this configuration, VLAN 101 has unrestricted access to communicate with VLANs 102 and 103, as well as access to the internet. On the other hand, VLAN 103 is limited to communication with VLANs 101 and 102 but does not have internet access.
07-12-2023 10:57 AM - edited 07-12-2023 11:35 AM
There is nothing wrong with your configuration ie. it should work because the acl is correct and is applied in the correct direction.
Is there any other path the clients could take to get to the internet, are you running HSRP etc. ?
Jon
07-18-2023 06:11 AM
Jon:
All our sites are connected via SD-WAN.
07-12-2023 03:41 PM
hi,
you can try using private VLAN config.
07-13-2023 07:01 AM
Is there a way to block ping to all the vlans. We want to confirm that there is no communication via ping.
07-13-2023 07:10 AM
meaning between all VLAN ?
if yes
vlan x
ip add x.x.x.x
ip access-group icmp IN
ip access-list icmp
deny icmp x.x.x.x any
permit ip any any
that it
07-13-2023 07:11 AM - edited 07-13-2023 07:13 AM
If you want to block ping from 192.168.103.x to 192.168.101.x and 192.168.102.x add these lines at the top of your 103 acl -
deny icmp any 192.168.101.x echo
deny icmp any 192.168.102.x echo
as I said previously your configuration is correct so something else is happening here.
Jon
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