MX67 - ipv4?

[dmiss]

I'm trialing out a MX67 connected to a Meraki Cellular gateway. I'm looking at the firewall rules on the MX and am only seeing Layer 3 rules for ipv6, none for ipv4. Does the MX only do ipv6 inbound layer 3 firewalling? 

[alemabrahao]

Inbound rules are just for IPV6, if you want to create a rule for IPV4 use Layer 3 Outbound Firewall Rules.

[dmiss]

Hmmmm, could you explain the logic behind that? So any outbound rules creates the equiv. inbound rule as well on the back end for ipv4?

[alemabrahao]

On the MX, outbound traffic refers to traffic originating from one VLAN that is destined for another VLAN or traffic originating from the LAN that is destined for the Internet or a remote network that is located over a static LAN route.

The inbound rules are destinated for traffic coming from the internet.

https://documentation.meraki.com/General_Administration/Cross-Platform_Content/Using_Layer_3_Firewal...

[Brash · Accepted solution]

By default, the MX will block all inbound traffic that isn't return traffic from an outbound flow (as any firewall/NAT router would).

If you want to allow traffic inbound, you can open a case for support to enable inbound ipv4 firewall rules.

This would typically only be used in a No-NAT IP-VPN/MPLS scenario.