Chas wrote: > *snip* > >> HOWEVER - you may need to: >> >> - allow for slow / failed response >> >> AND/OR >> >> - replace dodgy nameservers with better ones. >> >> AND/OR >> >> - run a local caching, recursing DNS that can keep the records asked for >> up-to-date between erratic responses. >> >> AND/OR >> >> - add a commonly-accessed but problematic far-end to /etc/hosts >> > > I don't understand what you mean by this last point. Could you elaborate > on that one? > > thanks, > Chas. >
man hosts If you have significant traffic from a specific host that commonly fails or times-out on DNS lookup, AND you otherwise feel you can 'trust' it, you can manually enter it in /etc/hosts, which is (normally) checked before making a (remote) DNS query. We do this, for example, on 'industrial' servers of our own, such as Disaster-Recovery file-storage beasts, that do not otherwise run MTA's *except* to send in their daily & weekly security reports. These won't ever have 'proper' MX records, 'coz they do not otherwise need them. CAVEAT: Regular checking and maintenance is a good idea, as far-end IP may change. NB: Same effect as granting a host a 'free pass' in Exim acl's. Which method is 'easier' is up to the rest of your environment. Side Note; If you have a long-lease DHCP IP on a SME/residential link, you can even make those look 'regular' this way. But only to 'yourself'.. ;-) Handy for testing certain things anyway... HTH, Bill -- ## List details at http://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
