DaHai8
Posts: 55
Joined: Fri Jul 31, 2015 9:21 am

Force eth0.0 route to eth0?

Wed Apr 05, 2017 5:37 am

Here's a simplified version of my previous post:

If I have PiA and PiB, its fairly simple to make PiA a gateway for PiB by setting the 'static routers=PiA' on PiB in /etc/dhcpcd.conf

But what if I want/need to set up two IP addresses on a Pi and route eth0.0 to eth0 ?

I've done that, but because the route table shows 2 default routes, the one with the lowest Metric is being used by both interfaces (eth0 & eth0.0)

Is there any way to force Default Route Metric 204 to be used by eth0.0 and Default Route Metric 202 to be used by eth0 ?

/etc/network/interfaces

Code: Select all

iface eth0 inet manual

auto eth0.0
iface eth0.0 inet manual
    vlan-raw-device eth0
/etc/dhcpcd.conf

Code: Select all

interface eth0
  static ip_address=192.168.3.50/24
  static routers=192.168.3.3
  static domain_name_servers=8.8.8.8 8.8.4.4

interface eth0.0
  static ip_address=192.168.3.51/24
  static routers=192.168.3.50
  static domain_name_servers=8.8.8.8 8.8.4.4
route

Code: Select all

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         192.168.3.3     0.0.0.0         UG    202    0        0 eth0
default         192.168.3.50    0.0.0.0         UG    204    0        0 eth0.0

User avatar
DougieLawson
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Joined: Sun Jun 16, 2013 11:19 pm
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Re: Force eth0.0 route to eth0?

Wed Apr 05, 2017 12:05 pm

Having default routes on more than one interface (even if it's a virtual interface) isn't going to do anything useful. Things will just get confused.

Pick an interface that has the true route to the public internet and assign just one "static routers" line in /etc/dhcpcd.conf to that interface.
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