Hello,

ok, lets start from the end: "4: After dtnping both can see each other". This is perfectly normal, considered B knows A (e.g. from static configuration) but for whatever reason A does not know B. When you send bundle from B to A, B will establish a TCP Convergence Layer connection to A. After the handshake, A knows B as neighbor (because it actually introduced itself by connecting). It may happen that after a time IBR-DTN closes the TCP connection when there is no traffic, and subsequently, if there is no other discovery mechanism, A will loose B as a neighbor.

The question is, why does A not see B after a while:

1. If you use statically connected neighbors: Maybe you have not configured B as a static neighbor in A's configuration 2. If you have discovery enabled, maybe the discovery bundles go only one way. This MIGHT also happen if the IPND discovery is bound on a wrong network interface (i.e. B uses eth0 to connect to A, but IPND is bound on eth1 -> The IPND messages sent by B will never reach A, but depending on the configuration of the network stack B might still receive IPND bundles received through eth0). If you rely on IPND, tcpdump might help detecting where discovery packets are going.

To say more you might check or post the configuration sectiosn of A and B with static node configurations, static routes and the section on discovery if any.

Sebastian

Am 12.08.2013 um 11:30 schrieb Francisco Cuesta ndarkness@gmail.com:

Hello,

I'm facing some issue with ibrdtn, the main scenario is described in the picture attached. The point is that both computers have ibrdtn installed, and with the same configuration. On certain time, ibrdtn node A cannot see node B, just mention that node A is a raspberry pi wroking with ibrdtn packages.

Thanks in advance,

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