Description of the menu options
ELSA LANCOM DSL/10 Office
R38
WAN-filter-
table
This table allows you to enter specific ranges of destination ports. If packets with the
entered ports are received from the WAN side, they will not be forwarded (firewall
function).
The WAN port filters are defined in a table similar to the LAN filter table:
The fields in the table have the same meaning as in the LAN filter table, with the
following exception:
K
Dst-address, Dst-netmask
A subnetwork of the local network for which the filter is valid can be entered here.
A destination address of 0.0.0.0 means that the filter is applied to all computers. A
network mask of 0.0.0.0 means that the filter is applied to all networks (which also
means all computers).
The table entries are sorted in a similar fashion to the IP router table:
K
Longest network mask is placed on top.
K
For two network masks of equal length, the one with the smaller IP address is placed
on top.
Network masks and IP addresses of 0.0.0.0 can be used as “wildcards“. Specified
computers and networks may be simultaneously subjected to targeted filtering while
others pass the router unfiltered.
The tables are processed from top to bottom. As soon as a matching filter is found, the
packet is handled accordingly.
Proxy-ARP
This option allows you to activate or deactivate the proxy ARP mechanism (default: 'Off').
This function permits data to be transmitted to IP addresses within the same logical
network as the sender, e.g. when linking individual workstation computers (teleworkers)
to the corporate network via TCP-IP.
Loc.-routing
Local routing enables the router to forward data packets via the local network. The local
routing is necessary if the router, as the default gateway for the workstations receives
packets for destination networks to which it cannot establish a connection itself. If the
router cannot return the address of the appropriate router to the workstation via ICMP, it
will forward the data to the corresponding router itself (see also 'Local Routing'). Since
this setting increases network utilization in the LAN, the default setting is 'Off'.
Setup/IP-router-module/Routing-method
The router offers two methods for IP routing, which can be separately set for IP and ICMP
packets. Both methods are based on the evaluation of the field 'Type-of-service' in the
IP header.
Idx.
D-st.
D-end
S-st.
S-end
Dest
Dst-netmask
Prot
WIN
53
53
137
139
0.0.0.0
0.0.0.0
TCP and
UDP
