[nos-bbs] TUN0 addressing w/JNOS atop Linux

maiko at pcs.mb.ca maiko at pcs.mb.ca
Wed Jan 11 22:39:23 EST 2006

Hi Jay,

> This box will be configured as a HamGate, so his Public IP on his eth0
> interface ( *MUST* be delivered to the JNOS application
> because he *will* be running IPIP encapsulation to all the other HamGates
> across the world and this IP is what's published in encap.txt.

How is he connected to the internet ? By the looks of the
hostname, I am guessing CABLE or DSL *direct* from the modem
to the computer. Am I correct ?

> shell ifconfig tun0 pointopoint mtu 1500 up

Nope ! If he is connected direct to the internet he'll have to have
something like the following :

 ip address
 shell ifconfig tun0 pointopoint mtu 1500 up'
 shell ifconfig tunl0 up

NOTE: your NOS now has an ip address of, but the gateways
entry will be going to - and LINUX does the ENCAP !

The encap.txt can not be used inside of JNOS, instead he would have
to have a munge script to process the encap.txt on the linux side,
since the linux will do the TUNNELING (ip-ip).

Don't confuse the TUNL0 (ip-ip tunneling) with the TUN0 (network device).

I hope this is not too confusing. But that's what I *used* to do. Having
a firewall/router (ADSL router) box is handy, especially with the DMZ
feature, you can actually tell the router to DMZ to the JNOS side of
the TUN link between JNOS and Linux ( ptp
for example), then you can do the encap.txt inside JNOS like before.

Hopefully that's enough for you to play with for now.

Good luck.


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