thakur%cfa201@harvard.harvard.edu (Manavendra K. Thakur) (08/08/89)
Hi all, After installing the new libc_resolv.so.sun3 library from uunet, we noticed that in addition to programs like finger and telnet, rpc.bootparamd was also using the nameserver to resolve hostnames. How do other sites feel about this? Are you worried about the fact that you are dependent on an outside service in order to boot? I know that nameserver queries are quite fast and that the nameserver system in general is fairly robust (what with secondary servers and stuff). However, what if our link to the outside world (which is how we access our domain's authoritative nameserver) goes down for a day or so? Am I correct in assuming that our diskless clients won't be able boot? It seems that we are putting ourselves at the mercy of a highly critical point of single failure here, and I'm not sure how to best deal with it, or even if it's an issue worth worrying about. If it is worth worrying about, one possible way to approach the problem is for Sun to rewrite the bootparamd code to provide some additional protection and redundancy. In particular, I think it would be good for Sun to integrate some sort of hierarchical hostname resolution procedure into the bootparamd and gethostby{name,addr} code. For example, if the nameserver times out, then try a YP call if ypbind is running. Failing that, the code should look in the local /etc/hosts as a last resort. (Of course, there may already be some sort of hierarchical procedure set up. The SunOS 4.0.3 man page for gethostbyname doesn't mention anything about this, and we don't have access to Sun source code.) Comments and perspectives from other sites? Manavendra K. Thakur System Manager, High Energy Division Harvard-Smithsonian Center for Astrophyics thakur@cfa.harvard.edu thakur%cfa201@harvard.harvard.edu
tank@apctrc.trc.amoco.com (Jon A. Tankersley) (09/02/89)
I'd set up my own nameservers for my local network and let bootparamd use them when booting. What I have in place is ypserv/named. I keep the local network info in the local yp and named resolves everything else. This works fine with redundant nameservers - you're supposed to have two anyway, but loss of the primary in a catastrophic fashion (unplug, crash, etc.) will hang telnet,rlogin, etc. 4.1 is supposed to fix this. -tank-