Quadro4Li Manual II: Administrator's Guide
Administrator’s Menus
Quadro4Li; (SW Version 5.3.x)
113
Advanced PPP Settings
The
Advanced PPP Settings
are used to enable/disable certain parts of the negotiation process during connection establishment. These settings
are available only if Quadro has a PPPoE WAN interface.
Attention
: Disabling any of the services below may cause problems when establishing a connection including the complete connection failure. The
default settings should be changed only if the ISP (Internet Service Provider) specifically requires it or if the peer system has problems with one of
the services listed below. More information about these services can be found at:The
Advanced PPP Settings
page offers the following group of checkboxes:
Enable automatic PPP restart at
checkbox is used to select the time when the PPP connection will automatically be restarted. The checkbox
selection enables
LCP echo failures
text field that indicates the number of the LCP echo failure packets received before the PPP connection will be
considered as dead and will be restarted.
Disable CCP (Compression Control Protocol) negotiation -
this option should only be selected if the peer system is not
working properly. For example, if it is not accepting the requests
from the PPPD (Point-to-Point Daemon) for CCP negotiation.
Disable magic number negotiation -
with this option, PPPD
cannot detect a looped-back line. This option should only be
selected if the peer is not working properly.
Disable protocol field compression negotiation in both the
receive and the transmit direction –
with this option,
no
protocol field compression will take place.
Disable Van Jacobson style TCP/IP header compression in
both the transmit and the receive direction –
with this option,
no negotiation of TCP/IP header compression will take place
and the header will always be sent uncompressed.
Disable the connection-ID compression option in Van
Jacobson style TCP/IP header compression -
with this
option, PPPD will not compress the connection-ID byte from
Van Jacobson and will not ask the peer to do so.
Disable the IPXCP and IPX protocols -
this option should only
be selected if the peer is not working properly and cannot
handle requests from PPPD for IPXCP negotiation.
Fig. II-191: Advanced PPP Settings page
VPN Configuration
A
VPN (Virtual Private Network)
is established to connect two local networks (intranets) securely over the Internet securely. The VPN routers
manage authentication between servers and clients and handle data encryption for the connection. Only authorized users may access the network
and the data exchange cannot be intercepted.
VPN connections
are, in many ways, like every Internet connection, they are based on IP addresses, which means, the concerned VPN gateways
must authenticate the IP addresses of their respective partner’s VPN gateways. Each time a specific VPN is to be established, usually the same IP
addresses are expected. This will not create problems if both VPN partners have fixed WAN IP addresses. There may be circumstances reasons to
prefer dynamically allocated IP addresses. To enable devices that use a variable IP address as part of a VPN, they are turned into “Road Warriors”.
For example, at this point they are able to reach their corporate network via authentication at the company's VPN gateway device. This VPN gateway
device must have a fixed IP address for Internet access. Every VPN needs at least one VPN gateway with a fixed IP address.
The partner devices of a VPN must have different WAN IP addresses, and if they are connected to local area networks, these LAN’s must have
different IP addresses. As all Quadro devices have the same default IP addresses on delivery, at least one of them must be reconfigured in order to
set a new IP address.
Quadro supports several kinds of VPN connections such as
IPSec
,
L2TP
and
PPTP
.
The
VPN Configuration
page offers IPSec Configuration and
PPTP/L2TP Configuration links that lead to the corresponding
feature settings pages.
Attention:
It is strongly recommended not to run different types
of VPN tunnels between the same endpoints simultaneously.
Fig. II-192: VPN Configuration page
An IPSec connection includes authentication and encryption to protect data integrity and confidentiality. VPNs are “virtual” in the sense that
individuals can use the public Internet as a means of securely accessing an internal network. Once the IPSec connection is established, users have
access to the same network resources, addresses, and so forth as if they were connected locally. VPNs are “private” because the data is encrypted
between two VPN gateways. Encryption makes it very difficult for anyone to intercept data and capture sensitive information such as passwords. The
Quadro can be set up to act as a VPN router when connected to the Internet with a fixed IP address or as an IPSec connection Road Warrior when
using dynamic IP addresses.
