Westermo RedFox Series User Manual
Page 395
Westermo OS Management Guide
Version 4.17.0-0
b)
a)
Switch
6
VLAN 3
7 8 9
Switch
4
5
6
VLAN 2
Switch
1
2
3
VLAN 1
VLAN 4
Switch
10
10
9
8
7
6
5
4
3
2
1
VLAN 1
VLAN 2
VLAN 3
VLAN 4
vlan1
vlan2
vlan3
(Routing)
(Switching)
VLANs
Interfaces
Network
Ethernet/DSL
Ports (1−10)
(vlan4)
pppoe0
1
Serial
Port(1)
modem0
Routing
WeOS Layer 2/3 Switch
Network
Interfaces
vlan1 vlan2 vlan3 (vlan4)
pppoe0
modem0
Ethernet/DSL
Router
Serial
Figure 19.1: A network interface is associated with each VLAN, and VLANs are in
turn associated with Ethernet (or DSL) ports as shown in figure a). Furthermore,
when using PPPoE, a PPP network interface will be created and mapped on top
of an associated VLAN interface, see pppoe0 and vlan4. The routing switch can
conceptually be seen as a router connecting a set of switches, as shown in figure
b). In this sample setup, port 6 is shared by VLANs 2 and 3 (by use of VLAN
tagging).
❼ Loopback network interface: The loopback interface lo is a logical network
interface, which is always present. Its primary IP address cannot be changed,
but it is possible to add secondary IP addresses, which can be useful in some
situations,e.g., for OSPF (
❼ GRE interfaces: (only for WeOS Extended) For every configured GRE tunnel
), an associated GRE network interface is created.
❼ SSL interfaces: (only for WeOS Extended) For every configured SSL VPN
tunnel (
), an associated SSL network interface is created.
❼ Blackhole interface:
WeOS has a hidden blackhole interface (”null0”),
which can be used to avoid routing loops in case of incomplete subnetting,
or to avoid that VPN traffic is forwarded towards the default gateway when
the VPN tunnel is down. See
shows how VLAN interfaces (vlan1-vlan4) are mapped to VLANs and
ports, i.e., Ethernet and DSL ports. When using PPPoE, a PPP interface is cre-
ated on top of a VLAN interface (see pppoe0 and vlan4 in
). modem0
represents the network interface when running PPP over a serial port. The GRE
and loopback interfaces are logical interfaces not directly associated with any
physical port.
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