ron@brl-sem.ARPA (Ron Natalie <ron>) (07/28/86)
In the last few weeks there have been an increasing number of people using the top level Internet domain names as part of the hostnames in the from lines and message-ids. This is just fine except for the fact that some of these people have no entry in the respective name servers for these hosts. If your address is going to end in .UK, .ARPA, etc..., you must have at least an MX record for your host in Internet domain servers. If you don't, it is impossible to determine whether you are reachable to the internet or not. When you use .UUCP or .BITNET, it is relatively obvious, and we know how to bounce things back, and we can rewrite them in the USENET<->INTERNET gateways so they are legal on the Internet side. However, when you use something that is looks like a valid Internet address, but isn't, no one can respond to it. Prime offenders are certain hosts in the AC.UK domain and some wierd host who claims to be pavepaw.ucb-arpa.arpa. -Ron
stephen@comp.lancs.ac.uk (Stephen J. Muir) (08/06/86)
In article <378@brl-sem.ARPA> ron@brl-sem.UUCP writes: >In the last few weeks there have been an increasing number of people >using the top level Internet domain names as part of the hostnames in >the from lines and message-ids. Leave message-ids out of this. So long as they contain a unique string, that's fine. >This is just fine except for the fact >that some of these people have no entry in the respective name servers >for these hosts. If your address is going to end in .UK, .ARPA, etc..., >you must have at least an MX record for your host in Internet domain >servers. If you don't, it is impossible to determine whether you are >reachable to the internet or not. When you use .UUCP or .BITNET, it >is relatively obvious, and we know how to bounce things back, and we >can rewrite them in the USENET<->INTERNET gateways so they are legal >on the Internet side. However, when you use something that is looks >like a valid Internet address, but isn't, no one can respond to it. Hosts in the UK are expected to register in the NRS, which automatically filters through to MX records. If a UK host has an MX record, that should be used. In practice, such use will cause the mail to be sent (transparently) through cs.ucl.ac.uk. This host is directly connected to the INTERNET. Sites on BITNET should use the gateway "UKACRL". If there is no MX record, then neither of these gateways will know about the host. In this case, as a last resort, the gateway "ukc.uucp" will be the only route. It is preferable not to use this gateway because the UK site is charged for both incoming and outgoing mail through this one. However, if there is no choice ... You say .UUCP and .BITNET are obvious. The answer for .UK is to use the algorithm above. Finally, I notice that some sites think they can tack on a .UUCP and get away with it. E.g.: user@umd5.umd.edu.uucp Although I sympasise due to the necessary hooks not being in Rn and inews, they should not be presenting addresses such as the above. -- EMAIL: stephen@comp.lancs.ac.uk | Post: University of Lancaster, UUCP: ...!mcvax!ukc!dcl-cs!stephen | Department of Computing, Phone: +44 524 65201 Ext. 4120 | Bailrigg, Lancaster, UK. Project:Alvey ECLIPSE Distribution | LA1 4YR