How to Increase MTU on Virtual Wire interfaces of the Palo Alto Firewalls

• Configure MTU on Virtual Wire(Vwire) interfaces of the Palo Alto Firewalls.
• Change MTU on Virtual Wire(Vwire) interfaces of the Palo Alto Firewalls.

• Palo Alto Firewalls.
• Virtual Wire interfaces configured.

• The Virtual Wire interfaces do not have an option to set the MTU.
• Instead, these interfaces use the global MTU settings.
• Interface ethernet1/3 is a Virtual Wire (Vwire) interface.
• The global MTU settings can be checked using the following command :-

> show system setting jumbo-frame
Device Jumbo-Frame mode:                           off
Maximum of frame size excluding Ethernet header:   1500
Current device mtu size:                           1500

> show system state filter-pretty sw.dev.interface.config
ethernet1/3: { 
    hwaddr: 00:50:56:xx:xx:xx, 
    mtu: 1500,

1. From the CLI, the global MTU can be increased by enabling Jumbo Frames (requires a reboot) , which in turn will increase the MTU on the Virtual Wire interface :

> set system setting jumbo-frame on

2. After enabling Jumbo Frames on the Firewall, the settings and MTU on the Virtual Wire interface can be seen as follows :-

> show system setting jumbo-frame 
  Device Jumbo-Frame mode:                           on
  Maximum of frame size excluding Ethernet header:   9216
  Current device mtu size:                           9192

> show system state filter-pretty sw.dev.interface.config
  ethernet1/3: {
      hwaddr: 00:50:56:xx:xx:xx,
      mtu: 9192,

How to Enable/Use/Disable/Check Jumbo Frame Support on a Palo Alto Networks Firewall