bigcouch stunnels unable to communicate on vagrant

At least on my vagrant nodes couch1 and couch2, my bigcouch nodes were not connecting their epmd stunnels, and I found this in the logs:

[  627.960275] iptables denied: IN=eth1 OUT= MAC=08:00:27:01:22:a8:08:00:27:9f:ab:80:08:00 SRC=10.5.5.44 DST=10.5.5.52 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=27690 DF PROTO=TCP SPT=53214 DPT=14369 WINDOW=14600 RES=0x00 SYN URGP=0 

when I cleared out shorewall, things worked fine.

I'm not sure yet if this is a vagrant-only issue or a larger issue.

(from redmine: created on 2013-11-25, closed on 2014-04-17, relates #5444 (closed))