Service redundancy : CARP, wackmole/spread, 4.x / 5.x

[Norberto Meijome]

Hi all,
I'm looking into adding some automatic failover for some services. I'd 
like to hear comments / advice on suitability of either CARP / FreeVRRP 
/ wackamole + spread for these 2 different setups (see below)
The setups are completelly independent of each other, so different 
solutions / approaches for each are OK.  Of course, I'm not interested 
in adding special hardware to do any of this, but if there are 
*significant* advantages of a hardware solution, i'd like to hear too :).

Setup 1) : - FreeBSD 4.11 Server, 3 x NICs (fxp, LAN/WAN/DMZ).
 - Firewall (ipf, but thinking of moving to ipfw), ipnat
 -  about 4 jails (secure FTP, email gateway with antispam, and AV).
  - Unmanaged switches used throughout.
  - No mysql / DBs.
  - email load is low (20 LAN users, but *heavy* users).
The idea is to add another server and be able to gracefully take over 
all the functionality with no or very minimum downtime.
For this setup, I was thinking of CARP, but it isn't supported in 4.x?


Setup 2): - 4 x FreeBSD 5.4 Web Servers, 2 NICs (Wan + Private Lan), 
utilising a full 100 Mbps link overall. (not sure if important, but each 
server also has HP's iLO standard on its own CAT 5, to the same switch).
 - Behind Cisco managed switch.
 - Apache 2.0, no DB in place.
 - Currently on a simple DNS round-robin setup.
 - No VRRP running on other switches on this segment of the datacentre, 
AFAIK
- How would CARP with arpbalance work on this situation? (would have to 
change the DNS to 1 IP,the virtual IP right?) Or is it better to go 
wackmole/spread? I had some problems a few years ago with wack/spread on 
8 servers running 4.x : if a server went down, another would pick up the 
IP..but never release it when the original came back up - never figured 
out what the problem was (possibly config?)



thanks in advance for your help & comments,
Beto