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User manual XC-32 XC-320 XC-4200
p
In case of a
Dial-IN
access, it uses in priority IP address specified in the user form (see
IV.7.6 - Optionnal remote IP address).
p
If the form does not contain an optional remote IP adress, it takes the IP address
specified in the Remote IP field from the PPP form.
p
If this address is already allocated to another interface, it takes the next free address.
example : Remote IP contains 192.168.5.1
User A connected
IP address 192.168.5.1
User B connected
IP address 192.168.5.2
User A disconnected
IP address 192.168.5.1 free
User C connected
IP address 192.168.5.1
If
Remote IP
contains
255.255.255.255
, Xcell will accept the address provided by the
remote host.
If
Remote IP
contains
0.0.0.0
,
Xcell will negotiate the next free IP address to its network
interface.
If
Remote IP
field contains a network address, Xcell will accept the address provided by
the remote
host (See X.5 - Dial-OUT connection).
WARNING !!
The network administrator will have to insure that IP addresses, susceptible
to be provided by Xcell, are not used by other machines.
X.7 - Compression
Xcell bears BSD compression over a PPP link.
In case of PPP connection through modems between two Xcells, please avoid to active
V.42bis compression from modems and the BSD compression for Xcell together..
X.8 - Proxy-ARP
In an Ethernet-located TCP/IP network, each machine is both characterized by its IP
address and by is MAC address (Medium Access Control). For an IP frame to be lead
from one machine to another, you previously have to encapsulate it in an ETHERNET
frame. This implies that an A machine dispatching an IP frame to a B machine must
necessarily know B’s MAC address. To achieve this, each machine manages an IP and
MAC address matching table. This ARP table is dynamically built. Its entries are
determined according to the needs and are destroyed after a certain time. If the A
machine can’t find in its ARP table an entry giving the B machine’s MAC address, it will
make an ARP request to all the network physically present machines. Theoretically, only
the machine corresponding to this IP address can react and issue its MAC address to the
B machine.
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