Westermo MR Series - Manual (Page 185)

185 6622-3201
Web Interface and Command Line Reference Guide www.westermo.com
Remote access options:
The Remote access options parameter can be set to “No restrictions”, “Disable management”,
“Disable return RST” or “Disable management & return RST”. When set to “No restrictions”,
users on this interface can access the unit’s Telnet, FTP and web services for the purpose of
managing the unit.
When set to “Disable management”, users on this interface are prevented from managing the
unit
via Telnet, FTP or the web interface. When set to “Disable return RST”, whenever the unit
receives a TCP SYN packet for one of its own IP addresses with the destination port set to an
unexpected value, i.e. a port that the unit would normally expect to receive TCP traffic on, it
will reply with a TCP RST packet. This is normal behaviour.
However, the nature of internet traffic is such that whenever an internet connection is estab-
lished, TCYP SYN packets are to be expected. As the router’s PPP inactivity timer is restarted
each time the unit transmits data (but not when it receives data), the standard response of the
unit to SYN packets, i.e. transmitting an RST packet, will restart the inactivity timer and prevent
the unit from disconnecting the link even when there is no “genuine” traffic. This effect can be
prevented by using the appropriate commands and options within the firewall script. However,
on MR and DR series, or where you are not using a firewall, the same result can be achieved
by selecting this option, i.e. when this option is selected the normal behaviour of the unit in
responding to SYN packets with RST packets is disabled. The option will also prevent the unit
from responding to unsolicited UDP packets with the normal ICMP destination unreachable
responses.
The “Disable management & return RST” option prevents users from managing the unit via the
Telnet, FTP and web interfaces and also disables the transmission of TCP RST packets as above.
Dial-out prefix:
When making outgoing PPP calls, the value specified by the Dial-out Prefix parameter is inserted
at the started of the actual number being called. This is normally used to access an outside line.
For example, when using AODI or BACP, the remote peer may provide a number to be used for
raising an additional B-channel to increase bandwidth. However, such a number will not normally
include the digits needed to connect to an outside line via a PABX.
Dial-out number:
To allow the unit to automatically make outgoing PPP calls you must enter the ISDN number to
dial in the Dial-out Number field. This might be the number of your Internet Service Provider
(ISP) or another router for example.
Dial-out number #2 #3 #4:
Optional extra dial-out numbers, if configured the dial-out numbers will be used in rotation.
Use GPRS/PSTN/external modem:
On models fitted with a GPRS module the PPP instance can be configured to use either GPRS,
PSTN or an external modem (connected via one of the ASY ports) instead of ISDN.
Detach GPRS on link failure:
If this parameter is set to “Yes”’, a GPRS PPP connection will detach and reattach after a failed
PPP connection disconnects. A PPP connection is deemed to have failed if the PPP was discon-
nected due to a firewall request, or if the PPP PING response timer expires.
Detach GPRS between connection attempts:
When this parameter is set to “Yes” the GPRS module will always detach (and reattach)
between PPP connections.
Username:
This is the username that should be used when authenticating with the remote system and is
usu ally only required for outgoing PPP calls.