On Wed, Mar 27, 2002 at 11:36:56AM -0700, Christian Cryder wrote: > > Ok, I'm at my wits end here and I'm hoping someone can give me some pointers > in the right direction. I am running RedHat 7.2 as a PDC, with Postfix for > my SMTP server, and UW's Imap server for POP. Here's what I'm observing: > > >From the local network...When I try to SSH into the linux box, connect via > POP, send mail, or log into the domain, it frequently takes up at least 30 > seconds to establish a connection. > > >From the outside world...When I try to SSH into the linux box, connect via > POP, or send mail, its a snap (just a few seconds at most) to connect to the > box.
Makes sense. You probably don't have a DNS server defined for your local addresses so it's eventually timing out. For your external hosts, those addresses do have valid nameservers and the query is being satisfied. > It almost seems as if something on the box is trying to do reverse dns > lookups on private IPs. I've been searching in vain to try and figure out > what controls this and how to either a) configure it to not do reverse dns > on private ips, or b) turn off reverse dns altogether. You need to choose option c) configure a DNS. There really isn't anything such as a "private IP". Many services will try to do a reverse-DNS lookup. For SMTP servers, having a functional DNS is to be considered essential. Using Bind 9, you can even configure a "split-DNS" that answers queries diff- erently depending on the source IP address. This would internal clients to be given internal addresses, and external clients to be given external addresses (or rejected internally). -- Ed Wilts, Mounds View, MN, USA mailto:[EMAIL PROTECTED] _______________________________________________ Redhat-list mailing list [EMAIL PROTECTED] https://listman.redhat.com/mailman/listinfo/redhat-list
