Digi APPLICATION NOTE 34 - Manual (Page 11)

11
3 TESTING
3.1 Simulate a failure
To test the fail over and recovery you will need to configure the PPP interface to ping a IP address that you
can easily stop responding to ICMP requests (either through the use of a firewall or by physically
disconnecting it from the network). You will also need to alter the firewall rule so it monitors the same IP
address that PPP 1 is pinging.
Once you have the IP address configured and the Digi Transport router is up on the main WAN link, remove
your test device from the network or adjust the firewall so it stops responding to the ICMP requests from the
Digi Transport router.
After approximately 30 seconds
the router should bring up PPP 4 (the dial-up connection). To confirm that
PPP 4 is up and being used you can:
• check the entries in Diagnostics - Event Log
• click on Diagnostics - Status > PPP > PPP 0 - 4 > PPP 4 > View and check the link is up and has a
valid IP address
• click on Configuration - Routing > Default Route 0 then scroll to the bottom and click on the button
‘Show IPv4 Routing Table’ to view the routing table which should show PPP 4 with a status of UP
and PPP 1 with a status of OOS.
• Also for dial-up, the routers OH and CD LED’s should be lit.
Once you have confirmed that the router has failed over correctly, re-enable the ICMP response or re-
connect the test device to the network. You should notice that after approximately 20 seconds, the router
drops the dial-up connection as the main PPP 1 link becomes available again.
This will again be shown in the event log, the routing table, the PPP 4 status should show Link Inactive, and
the OH & CD LED’s should go out.
4 CONFIGURATION FILES
4.1 Digi Transport Configuration Files
This is the relevant parts of the configuration file:
eth 0 IPaddr "10.1.51.2"
eth 0 mask "255.255.0.0"
def_route 0 ll_ent "PPP"
def_route 0 ll_add 1
def_route 0 deact_ent "PPP"
def_route 0 deact_add 4
def_route 1 ll_ent "PPP"
def_route 1 ll_add 4
def_route 2 ll_add 3
def_route 4 ll_add 4
ppp 1 IPaddr "0.0.0.0"
ppp 1 username "[email protected]"
ppp 1 epassword "encrypted"
ppp 1 timeout 0
ppp 1 aodion 1
ppp 1 autoassert 1
ppp 1 do_nat 2
ppp 1 firewall ON
ppp 1 pingip "1.2.3.4"
ppp 1 pingint 10
ppp 1 pingis ON
ppp 1 l1iface "AAL"
ppp 1 ipanon ON
ppp 1 pppanon ON
ppp 1 settledly 100
ppp 4 IPaddr "0.0.0.0"