Plenty of people have this type of setup, if you already know what you're
doing with LDAP from the existing installation you shouldn't have any problem
configuring it with Dovecot.
Thanks. That's what I would have thought, but I am clearly getting something wrong. I have dovecot with ldap installed, and I thought I had it configured to talk with our ldap server the same way the courier imap (which works fine) does, but all was getting was an authentication failure with timeout.
Tried running tcpdump on the ldap server to watch the exchange, but it didn't reveal much. I'm not an expert at reading tcpdump output, but it looks like when I connect to the dovecot imap server and try to log in, it opens a connection to the ldap server and then.... nothing happens. I don't see any data exchange occurring. But as I said, I am not an expert at reading tcpdump output.
nb-200# tcpdump -vv port 389
tcpdump: listening on fxp0, link-type EN10MB (Ethernet), capture size 96 bytes
15:12:53.378192 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], length: 60) nb-212.win.net.64502 > nb-200.win.net.ldap: S [tcp sum ok] 1650141152:1650141152(0) win 65535
15:12:53.378319 IP (tos 0x0, ttl 64, id 31077, offset 0, flags [DF], length: 64) nb-200.win.net.ldap > nb-212.win.net.64502: S [tcp sum ok] 4093352694:4093352694(0) ack 1650141153 win 65535
15:12:53.378457 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], length: 52) nb-212.win.net.64502 > nb-200.win.net.ldap: . [tcp sum ok] 1:1(0) ack 1 win 1026
15:12:53.378470 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], length: 92) nb-212.win.net.64502 > nb-200.win.net.ldap: P 1:41(40) ack 1 win 1026
15:12:53.381078 IP (tos 0x0, ttl 64, id 31084, offset 0, flags [DF], length: 66) nb-200.win.net.ldap > nb-212.win.net.64502: P [tcp sum ok] 1:15(14) ack 41 win 33304
15:12:53.484057 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], length: 52) nb-212.win.net.64502 > nb-200.win.net.ldap: . [tcp sum ok] 41:41(0) ack 15 win 1026
15:13:03.979700 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], length: 166) nb-212.win.net.64502 > nb-200.win.net.ldap: P 41:155(114) ack 15 win 1026
15:13:04.076671 IP (tos 0x0, ttl 64, id 33174, offset 0, flags [DF], length: 52) nb-200.win.net.ldap > nb-212.win.net.64502: . [tcp sum ok] 15:15(0) ack 155 win 33304
15:13:23.300900 IP (tos 0x0, ttl 64, id 35751, offset 0, flags [DF], length: 66) nb-200.win.net.ldap > nb-212.win.net.64502: P [tcp sum ok] 15:29(14) ack 155 win 33304
15:13:23.407040 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], length: 52) nb-212.win.net.64502 > nb-200.win.net.ldap: . [tcp sum ok] 155:155(0) ack 29 win 1026
^C227 packets captured
21204 packets received by filter
0 packets dropped by kernel