4.8 I keep getting the following errors: "collect: I/O error on connection" or "reply: read error from host.name". What will fix this?

If this is an error which is arising from just one host in particular then there is really nothing you can do as it's likely to be some sort of transient network error on their end of the connection. If the error comes with all connections, then your network link likely has some sort of problem. If you're on a PPP or SLIP connection check your MTU settings out first, as that is a common cause of network problems of this type.

On most Red Hat Linux machines, your MTU settings will be in /etc/sysconfig/network-scripts/ifcfg-ppp0. Here's what this file might look like:

   [root@ns network-scripts]# less ifcfg-ppp0 
   DEVICE="ppp0"
   ONBOOT="yes"
   USERCTL="yes"
   MODEMPORT="/dev/ttyS1"
   LINESPEED="115200"
   PERSIST="yes"
   DEFABORT="yes"
   DEBUG="no"
   INITSTRING='AT&F%A2=95@B0=2@M2=P%A4=0'
   DEFROUTE="yes"
   HARDFLOWCTL="yes"
   ESCAPECHARS="no"
   PPPOPTIONS='asyncmap 0'
   PAPNAME="somebody"
   REMIP=""
   NETMASK=""
   IPADDR=""
   MRU="1500"
   MTU="1500"
   DISCONNECTTIMEOUT=""
   RETRYTIMEOUT="5"
   BOOTPROTO="none"
   

What you should do is verify with your ISP what their MTU settings are on their NAS device and set yours to be the same.