
Performing the Initial Hardware Setup
3-12
Hewlett-Packard VPN Server Appliance SA3110/SA3150/SA3400/SA3450 Installation Guide
As a bridge, the VPN device ARP responds under the following
conditions:
1.
The ARP request is for an address that has been assigned to
an interface on the VPN device.
2.
The ARP request is for an address that has been assigned to
a remote user tunnel as a client IP.
3.
The ARP request is for an address that is currently in the VPN
device device’s ARP cache for an interface other than the
interface where the ARP request was picked up.
4.
If the ARP request is for an address that is not in the VPN
device device’s ARP cache for any of its interfaces, then the
VPN device broadcasts a new ARP request out of all
interfaces except for the interface where the original ARP
request was picked up. If a device responds to the VPN
device, the VPN device creates a new entry in its ARP cache
and behaves as in condition 3 in the preceding paragraph.
Note:
Note:
Note:
Note: ARP requests and responses can become a significant
percentage of your network traffic if the devices on your
network are misconfigured.
When Bridge
When Bridge
When Bridge
When Bridge
Mode Should Be
Mode Should Be
Mode Should Be
Mode Should Be
Used
Used
Used
Used
A VPN device should be configured as a bridge if you were going
to connect two physically separate network segments that
contain devices in the same logical subnet. This is often the case
when the VPN device is going to be connected between an
existing firewall and a corporate network (referred to as inline
configuration in the
Hewlett-Packard VPN Server Appliance
SA3110/SA3150/SA3400/SA3450 Network Layout Reference
Guide).
Note:
Note:
Note:
Note: The mode of operation of the VPN device does not affect
the firewall or tunneling functionality of the VPN device. The
physical interfaces of the VPN device can still be designated as
black and red, and firewall rules can still be defined to allow or
disallow IP traffic.
Next Step
Next Step
Next Step
Next Step
Connecting the Device to the Network (page 3-12)