[nos-bbs] JNOS axudp to BPQ on the same host?

[Darin Franklin]

I ended up installing BPQ on another host, 192.168.1.103, and I got that to work.  On 192.168.1.103, I saw that the UDP packets were arriving with a source address of 192.168.2.2, but I couldn't ping that from 192.168.1.103.  I added a route to 192.168.2.2 in my router, pointing it to gateway 192.168.1.102.  With that, I was able to connect both ways.

I also got the Internet connection to work by adding port forwarding in the router: 10093 UDP goes to 192.168.2.2.

I could not get JNOS to connect to BPQ on the same host using 192.168.1.102.  It only works if I send to 192.168.2.1.

Ping from JNOS does work.

jnos> ping 192.168.1.102
jnos> Resolving 192.168.1.102... 192.168.1.102: rtt 1

% sudo tcpdump  -i tun0 -n -vvv -p icmp
tcpdump: listening on tun0, link-type RAW (Raw IP), capture size 262144 bytes                                                       
21:12:40.561676 IP (tos 0x0, ttl 254, id 60, offset 0, flags [none], proto ICMP (1), length 32)                                     
    192.168.2.2 > 192.168.1.102: ICMP echo request, id 132, seq 0, length 12                                                        
21:12:40.561806 IP (tos 0x0, ttl 64, id 23618, offset 0, flags [none], proto ICMP (1), length 32)                                   
    192.168.1.102 > 192.168.2.2: ICMP echo reply, id 132, seq 0, length 12                                                          

I think that problem is in BPQ. It looks like it is receiving the message on 192.168.1.102, but it is sending the reply from 192.168.2.1.  There is not a way to make it bind to a single IP address.

% sudo tcpdump  -i tun0 -n -vvv -u port 10092
tcpdump: listening on tun0, link-type RAW (Raw IP), capture size 262144 bytes                                                       
21:47:12.795131 IP (tos 0x0, ttl 254, id 17, offset 0, flags [none], proto UDP (17), length 45)                                     
    192.168.2.2.10092 > 192.168.1.102.10092: [udp sum ok] UDP, length 17                                                            
21:47:12.910736 IP (tos 0x0, ttl 64, id 5353, offset 0, flags [DF], proto UDP (17), length 45)                                      
192.168.2.1.10092 > 192.168.2.2.10092: [udp sum ok] UDP, length 17                                                              

Anyway, that is a moot point now, since I have the remote hosts working.  I thought that running them on the same box would be easier to troubleshoot, but it just caused more trouble.


> On Sep 7, 2020, at 7:15 AM, M Langelaar <maiko at pcsinternet.ca> wrote:
> 
> Hi Darin,
> 
>> I use 192.168.1.102 (the RPi host address), then I cannot connect to BPQ.
>> attach axudp bpq 256 192.168.1.102 KE0NUC-3 10092 10092
>> jnos> c bpq KE0NUC-3
>> Trying KE0NUC-3 on port bpq...
>> (wait forever...)
>> 
>> How do I get this second case to work?
> 
> I don't know if that's the complete networking side of BPQ configuration
> you gave, but it's almost like you don't have IP forwarding enabled on linux.
> 
> Can you telnet (or probe ssh using telnet 22) from JNOS to your PI ?
> 
> May I ask why you want to switch from 192.168.2 to your PI address instead ?
> 
> Maiko, VE4KLM
>