Hot add Nic into Vyatta VM – no reboot required

Recently I was asked about how to add a nic to a Vyatta VM, my reply “add it in VMware and reboot”- their response “We cannot reboot”. I asked why they can’t reboot and they said “If we were to reboot this Vyatta (Bring down the Client VPNs) then we would have to send out an email a ton of clients and let them know” – huge ordeal .

So we need to add a nic via VMware, and then have Vyatta recognize that nic right away, with out a reboot. So I added the Nic (see image below) in VMware:


After I add the NIC, I can look on the Vyatta and see it still shows only two NICs.


So, VMware added the nic but Vyatta(debian) never sees it. After trying to ifup/ifdown , service network restart – and many other commands it could never find it.

So, what is needed – we have to rescan the PCI bus to find the nic. Most Linux users are probably like — ya of course you do! But I just reboot and it works. In this case cant reboot.

To Rescan the PCI bus, we have to first change our permissions on that file, echo into that file, than change the permissions back. The commands to do so are:


sudo chmod 0777 /sys/bus/pci/rescan

sudo echo 1 > /sys/bus/pci/rescan

sudo chmod 0220 /sys/bus/pci/rescan

After doing that look at your interfaces:


Now we see the interface and can configure it. This process should work with Debian no problem (since Vyatta is Debian).

One response to “Hot add Nic into Vyatta VM – no reboot required

  1. Didier November 5, 2016 at 5:37 pm

    excellent, just what I needed, thanks for the tip 🙂

Leave a Reply