ARP issue on vlan

commgdog

Hello,

I am working on setting up a simple vlan deployment with pfSense.

I have installed pfSense on one of my machines, and set up some VLANs

Interfaces:

em0 - WAN
em1_vlan40 - LAN_1
em1_vlan41 - LAN_2

I have assigned a static IP to the WAN from the IP's given to me by my ISP. All works well, I can ping out on WAN, etc.

I have set both LAN_1 and LAN_2 to static IPs on their interfaces (172.16.40.1/24 and 172.16.41.1/24 respectively).

I have set up a linux server using a static IP on LAN_1 (172.16.40.100).

For some reason, I am not able to ping out from my linux server to either pfSense or the internet.

There is no entry in my ARP table on pfSense for my linux server.

At first I thought it was an issue with the IP address on the linux server, but here is some strange behavior:

When I ping the linux server from pfSense on the LAN_1 interface, my linux server is then added to the pfSense ARP table and everything works properly. After that, my linux server can ping both pfSense and the internet. If I reboot pfSense, then it goes back to not adding my linux server to the ARP table, and nothing can get out.

I added another server to the linux server's LAN and was able to ping back and forth on the LAN just fine.

What would cause the issue with devices not getting automatically added to the ARP table on pfSense?

Thanks.

heper

Wrong switch configuration perhaps?

johnpoz

Yeah what is the configuration on your switch? You would be trunk on your connection to em1 on pfsense, and then the ports your linux boxes are on would be in the vlan you want them in.

commgdog

This is what my switch config looks like:

interface gigabitethernet9
description "pfSense - LAN (em1)"
switchport trunk allowed vlan add 40-50
!
interface gigabitethernet10
description "pfSense - WAN (em0)"
switchport mode access
switchport access vlan 10
!
interface gigabitethernet15
description "Linux eth0"
switchport mode access
switchport access vlan 40
!
interface gigabitethernet16
description "Linux eth1"
switchport trunk allowed vlan add 41-50
!

VLAN 10 is my WAN network where my addresses from my ISP are. It comes in untagged on em0 of pfsense
em1 is trunked 40-50 (I'm not using all VLANs currently, but they are there because I plan on using them in the future)

On the linux box, eth0 is untagged 40, this is the management VLAN.
eth1 of the linux box is tagged 41-50.

For testing, eth1 of the linux box isn't even up, I'm just trying to get VLAN 40 to work.

Derelict

What would cause the issue with devices not getting automatically added to the ARP table on pfSense?

Not getting the ARP broadcast from the switch.

Diagnostics > Packet Capture on LAN_1 and see what's really going on.