unhd (Roger Gonzalez ) (11/30/90)
System: Sun 3/160 running SunOS 4.1, *no* YP I had been having problems getting ftp, telnet, finger, etc. to use the nameserver. I received a suggestion to rebuild /usr/lib/libc.so with the inclusion of some .o's from libresolv.a. This worked pretty well; all address resolution was now done through the nameserver. Unfortunately, this makes /etc/hosts completely ignored. Its not *that* intolerable, but the /etc/hosts contained some convenient nicknames for local machines that the resolver doesn't know about. C'est la vie. Worse, however, is the fact that sendmail no longer knows what 'mailhost' is. Outgoing mail is completely dead with regards to non-local sites. Am I doing something wrong, or are there some changes that I need to make in sendmail.cf? thanks, Roger -- "The question of whether a computer can think is no more interesting than the question of whether a submarine can swim" - Edsgar W. Dijkstra rg@unhd.unh.edu | UNH Marine Systems Engineering Laboratory r_gonzalez@unhh.bitnet | Durham, NH 03824-3525
rbj@uunet.UU.NET (Root Boy Jim) (12/11/90)
In article <1990Nov30.135031.25038@uunet!unhd> rg@unhd.unh.edu (Roger Gonzalez ) writes: >System: Sun 3/160 running SunOS 4.1, *no* YP >I had been having problems getting ftp, telnet, finger, etc. to use the >nameserver. I received a suggestion to rebuild /usr/lib/libc.so with >the inclusion of some .o's from libresolv.a. This worked pretty well; >all address resolution was now done through the nameserver. Unfortunately, >this makes /etc/hosts completely ignored. Its not *that* intolerable, >but the /etc/hosts contained some convenient nicknames for local machines >that the resolver doesn't know about. C'est la vie. So add your nicknames to your nameserver database with CNAME records. The easiest place is in your named.local file. I put things there because (1) the info never changes (2) this is the one domain that everyone is an authority for. Purists may groan, as the information really doesn't "belong" there, but it works. ; ; @(#)named.local 1.1 (Berkeley) 86/01/21 ; @ IN SOA host.do.main postmaster.host.do.main ( 901106 ; Serial 3600 ; Refresh 300 ; Retry 3600000 ; Expire 14400 ) ; Minimum IN NS host.do.main 1 IN PTR LOCALHOST. ; ; *** Add Alises Here *** DON'T FORGET THE DOTS! ; mailhost. IN CNAME localhost. loghost. IN CNAME localhost. -- Root Boy Jim Cottrell <rbj@uunet.uu.net> Close the gap of the dark year in between
del@algol.mlb.semi.harris.com (Don Lewis) (12/19/90)
In article <114205@uunet.UU.NET> rbj@uunet.UU.NET (Root Boy Jim) writes: >In article <1990Nov30.135031.25038@uunet!unhd> rg@unhd.unh.edu (Roger Gonzalez ) writes: >>System: Sun 3/160 running SunOS 4.1, *no* YP > >>I had been having problems getting ftp, telnet, finger, etc. to use the >>nameserver. I received a suggestion to rebuild /usr/lib/libc.so with >>the inclusion of some .o's from libresolv.a. This worked pretty well; >>all address resolution was now done through the nameserver. Unfortunately, >>this makes /etc/hosts completely ignored. Its not *that* intolerable, >>but the /etc/hosts contained some convenient nicknames for local machines >>that the resolver doesn't know about. C'est la vie. > >So add your nicknames to your nameserver database with CNAME records. >The easiest place is in your named.local file. I put things there >because (1) the info never changes (2) this is the one domain that >everyone is an authority for. Purists may groan, as the information >really doesn't "belong" there, but it works. There is also an environment variable "HOSTALIASES" that you can set to a file name that contains aliases for hosts and the actual host names. You could put "mailhost whatever" in a file, and set the HOSTALIASES variable before starting sendmail. This feature allows users to define their own host aliases as well (it'll probabably break things if users uses these aliases in mail addresses unless the addresses are somehow canonicalized). This appears to be undocumented in the Sun man pages. I found out about it by looking at the Berkeley code and doing a strings on Sun's libresolve.a. -- Don "Truck" Lewis Harris Semiconductor Internet: del@mlb.semi.harris.com PO Box 883 MS 62A-028 Phone: (407) 729-5205 Melbourne, FL 32901
rickert@mp.cs.niu.edu (Neil Rickert) (12/19/90)
In article <1990Dec18.234957.29846@mlb.semi.harris.com> del@algol.mlb.semi.harris.com (Don Lewis) writes: > >There is also an environment variable "HOSTALIASES" that you can set >to a file name that contains aliases for hosts and the actual host >names. You could put "mailhost whatever" in a file, and set the >HOSTALIASES variable before starting sendmail. This feature allows users >to define their own host aliases as well (it'll probabably break things >if users uses these aliases in mail addresses unless the addresses are >somehow canonicalized). This appears to be undocumented in the Sun >man pages. I found out about it by looking at the Berkeley code and >doing a strings on Sun's libresolve.a. If you are smart you won't even try this. The ability to do this is a bug. The IDA sendmail sources, for example, unsetenv('HOSTALIASES') to prevent this. The problem is that it is terribly unreliable. Mail that comes in over the network uses the HOSTALIASES set before the daemon was started. Mail that is created by a local user depends on the HOSTALIASES set by that user. But if the mail can't immediately go out it is queued, and the next try it depends on the HOSTALIASES of the daemon again. For UUCP mail the value of HOSTALIASES will depend on whether the connection was started by cron, by a remote dial in, or by a local user issuing a 'uucp' command. The real secret for 'mailhost' is that the name is encoded right inside 'sendmail.cf'. Just edit 'sendmail.cf', and change 'mailhost' to the fully qualified domain name of the mail host. The rebuild the freeze file with 'sendmail -bz' (if you use a freeze file). Finally kill and restart the sendmail daemon. -- =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*= Neil W. Rickert, Computer Science <rickert@cs.niu.edu> Northern Illinois Univ. DeKalb, IL 60115 +1-815-753-6940
meggers@mothra.nts.uci.edu (Mark Eggers) (12/19/90)
Another way to do this is to set up the domain name system with a mailhost.domain as a CNAME to the real host. This seems to work with Sun 4.0x, and 4.1 running the supplied sendmail stuff (one slight hack to get it to recognize the fully qualified domain name as local), with a real sendmail (read sendmail 5.64 - IDA 1.3.4) as the mail host. /mde/