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Suggest to your network admin that he read RFC 1878, dated December 1995. A quote from it: For the sake of completeness within this memo, tables 2-1 and 2-2 illistrate some options for subnet/host partions within selected block sizes using calculations which exclude all-zeros and all-ones subnets [2]. Many vendors only support subnetting based upon this premise. This practice is obsolete! Modern software will be able to utilize all definable networks. That's one of the few places you'll ever see an exclamation mark in an RFC. Cisco began defaulting to having "ip subnet-zero" on in the late 1990's - with release 12.0 of IOS, the Cisco OS. While there's no problem with using the first subnet, there can be with using the last (all-ones) subnet, but only on misconfigured networks. Cisco describes this at http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080093f18.shtml#subnetzero TCP/IP went into service on the internet January 1, 1983. The people who developed its specs were very, very good, but they weren't quite omniscient. Some ragged spots have been cleaned up over the years, and this subnet zero stuff is one of them. (In fact, subnets not on class boundaries weren't initially part of TCP/IP at all.) Doug Lytle writes: > Our network administrator is giving me the information. Something about > you can't have all bit 0's on or 1's on. Not really sure why, I am > taking his word on it. > > Doug > > Dick St.Peters wrote: > > >>You can't use 10.100.1.1 in the 252 subnet mask. You have to start at > >>10.100.1.5 > >> > >> > > > >This limitation was abandoned long ago and is not applicable to > >virtually any modern system. > > > >The only exception I know of is Cisco routers, where the limitation > >applies unless the Cisco configuration command "ip subnet-zero" is > >included in the router config, which almost everybody does. > > > >-- > >Dick St.Peters, stpeters@xxxxxxxxxxxxx > >Gatekeeper, NetHeaven, Saratoga Springs, NY > > > > > ____________________________________________ Openvpn-users mailing list Openvpn-users@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/openvpn-users |