MX 84 (18.107.2) - Unable to block inter vlan routing

DarrenOC
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MX 84 (18.107.2) - Unable to block inter vlan routing

This should be really simple in blocking two VLANs from communicating with each other but this failing miserably.  I've created the two L3 outbound firewall rules as per below:

 

 

DarrenOC_0-1709215318707.png

 

When testing via the MX itself i'm able to ping through to devices on the 10.228.139.0/24 subnet from 10.228.138.0/24.

 

This can also be seen via a packet capture on the LAN:

 

DarrenOC_1-1709215482483.png

 

I'm 200 miles away from site so can't test locally before anyone asks 😉

 

 

Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
11 Replies 11
RaphaelL
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Is 10.228.138.1 a SVI on your MX ? 

 

I think that behavior is expected. I don't think you are able to ping hosts with that rule , but you can ping the default gateways. 

DarrenOC
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hi @RaphaelL the SVI's are on the MX itself.  Agree that pinging the SVI's may be possible due to traffic/packet flow but i shouldn't be able to ping the hosts which in this instance i can.

Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
RaphaelL
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Correct. 


I believe I saw that behavior in the documentation but I can't find it ... 

 

I believe locally sourced traffic will not abide by your layer 3 policies.  <-- This is probably the reason why. So you would probably need 2 hosts on the 2 vlans to test.

DarrenOC
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I could request a support ticket 😂 😉

Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
KarstenI
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I expect that this is something like it's also on the ASA. Traffic generated from the box itself is not subject to ACLs.

 

Can't you test it locally? 😉

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jimmyt234
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+1, I believe locally sourced traffic will not abide by your layer 3 policies.

DarrenOC
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so what we're saying is these rules could be working but there's just no way of me testing using the dashboard remotely?

Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
CptnCrnch
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I even bet that these rules will work. 😉

KarstenI
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I would be highly disappointed in you if you didn't deploy a full stack so that you can test from the APs for example ... 😉

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DarrenOC
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off to build a full-stack.....

Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
DarrenOC
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😂- there's always one.  Better get in the car

Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/

I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.
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