openswan connection terminated after some time without packet transport

Binary package hint: openswan

1. Install openswan
2. Configure openswan use only IPv4. Be sure to have one box *behind* a DSL router with IP-Adress change after a certain amount of time.
3. Configure your openswan server with a fixed IPv4 address in the internet.
4. Start openswan first on the server, second on the client.
5. Try to ping the server from the client. OK? If yes, config is OK.
6. Try to ping the client from the server. OK? If yes, config is OK.
7. halt both pings, leave openswan running on both boxes, but *do not have anything running trying to transfer packets*
8. Come back after at least an hour.
9. Try again to ping the server from the client. Doesn't work? Fine!
10. Try again to ping the client from the server: Doesn't work? Fine!
11. restart the openswan daemon on the server.
12. restart the openswan saemon on the client.
13. ping the server from the client. OK? Fine.
14. ping the client from the server. OK? Fine.
15. halt both pings. Wait again for at least an hour. Try again to ping. Not working?

OK. You've got it.
Openswan does not reconnect the tunnel after a longer period without any transmission. The tunnel stays down until both openswan is restarted on both sides.

Seen with:
Ubuntu 10.04.2 LTS
Ubuntu 10.10
Ubuntu 11.04b1

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: openswan 1:2.6.28+dfsg-5
ProcVersionSignature: Ubuntu 2.6.38-8.42-virtual 2.6.38.2
Uname: Linux 2.6.38-8-virtual x86_64
Architecture: amd64
Date: Tue Apr 12 21:11:28 2011
InstallationMedia: Ubuntu-Server 10.04.1 LTS "Lucid Lynx" - Release amd64 (20100816.2)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: openswan
UpgradeStatus: Upgraded to natty on 2011-04-08 (4 days ago)