kdb300: Using 2 Blue Heat/Nets as PPP routers to make a PPP link

Title: Using 2 Blue Heat/Nets as PPP routers to make a PPP link
Keywords: PPP, Modem, Call, Answer, BlueHeat/Net, Routing, BHN, Routers
Date: June 29, 2006
KDB: KDB-300
Revision: 0.02
Author: Support
Distribution: External

Synopsis

The Blue Heat/Net can be used as a PPP router. Two Blue Heat/Nets can be used to create a PPP link between 2 networks.

Abstract
You will need 2 Blue Heat/Nets with firmware version 1.17 or newer. Confirm this before you start because older versions of the firmware will not work. If your BHN does not have version 1.17 please email [email protected] and they can set you up with a newer firmware version.
This is useful in the following scenario:
PC1 → BHN1 → BHN2 → PC2

PC setup
Under the network TCP/IP settings, set PC1 default gateway to BHN1’s (Ethernet interface) IP address.
Under the network TCP/IP settings, set PC2 default gateway to BHN2’s (Ethernet interface) IP address.
PC1 and BHN1 should be on the same subnet (e.g. 192.168.42.0/24). PC2 and BHN2 should be on a different subnet (e.g. 192.168.43.0/24). The PPP link will with a third subnet (e.g. 192.168.0.0/24).

BHN Setup PPP configuration
Make the serial PPP connection between the 2 BHNs. Confirm that it works by starting a telnet session with one BHN and ping the (PPP) IP address of the other BHN. You need to know you have a working connection before attempting the next steps.


Example Setup

Modify the PPP chat scripts
In the WCM add to start the chat script:
#!/bin/sh
echo 1 > /proc/sys/net/ipv4/ip_forward

This line will allow packets to be routed between the PPP and Ethernet networks. This needs to be done with both BHNs.

Add ip_up file
Telnet into the BHN. Move to the /etc/ppp directory:
# cd /etc/ppp

copy a chat-answer file to ip-up:
# cp chat-answer.ttyS0 ip-up

This will give executable file permissions to the ip-up file. Check this by typing
# ls -l

You should see the listing as:
-rwxr-xr-x 1 0 0 75 Nov 30 00:48 ip-up

The important thing is that the file permissions contain an x, implying the file has executable file permissions. Things will not work if this is not there.
Edit the file using vi. Delete the contents of the existing file and add the following:
#!/bin/sh
route add -net 10.0.1.0 metric 0 netmask 255.255.255.0 dev ppp0

Replacing 10.0.1.0 for the network of the Ethernet side of the other BHN.

You will need to do this for both BHNs.
Reboot both BHNs.


Sample scripts from 2 BHNs:

PPP Answer BHN
options configuration file
debug
nodetach
noauth
crtscts
lock
192.168.0.10:192.168.0.254
115200
persist

chat configuration file
#!/bin/sh
echo 1 > /proc/sys/net/ipv4/ip_forward

pap-secrets configuration file
# Secrets for authentication using PAP
# client server secret IP addresses
test * test *

chap-secrets configuration file
# Secrets for authentication using CHAP
# client server secret IP addresses
test * test *

ip-up file
#!/bin/sh
route add -net 192.168.43.0 metric 0 netmask 255.255.255.0 dev ppp0

PPP Call BHN
options configuration file
debug
nodetach
noauth
crtscts
lock
192.168.0.254:192.168.0.10
115200

chat configuration file
#!/bin/sh
echo 1 > /proc/sys/net/ipv4/ip_forward

pap-secrets configuration file
# Secrets for authentication using PAP
# client server secret IP addresses
test * test *

chap-secrets configuration file
# Secrets for authentication using CHAP
# client server secret IP addresses
test * test *

ip-up file
#!/bin/sh
route add -net 192.168.42.0 metric 0 netmask 255.255.255.0 dev ppp0

End of KDB-300

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