One drawback with 1918 addresses on intermediate physical interfaces is that this too makes troubleshooting more difficult. Entities outside of your domain may troublsehoot problems in or through your network using traceroute. Traceroute timeouts will originate from the physical interface the TTL expired on. If this physical interface is numbered using 1918, then it's possible these return traceroute packets will get filtered somewhere on the return path.
nrf wrote: > > Depending on your network, that may be a perfectly acceptable trade-off. > > Or you can continue to use RFC1918 addresses on your WAN links, even if they > are on the public Internet (as long as you don't advertise these addresses > to a peer ISP). Hey, why not - nobody on the Internet is actually > interested in accessing your WAN links, they are interested in accessing > your end-hosts. So as long as your end-point addressing is publicly > routable, it doesn't really matter if your intermediary networks are not. > > ""Symon Thurlow"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Yes but then you lose troubleshooting capabilities etc. > > > > -----Original Message----- > > From: nrf [mailto:[EMAIL PROTECTED]] > > Sent: 13 October 2002 01:45 > > To: [EMAIL PROTECTED] > > Subject: Re: can I use a /31 subnet to the link between 2 routers eth > > [7:55480] > > > > > > Or even better, just use unnumbered interfaces. > > > > > > ""Bolton, Travis D [LTD]"" wrote in message > > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > > I would still use a /30 mask if I was using unregistered IP's. If I > > > was using standard IP's then maybe I would think about using the /31. > > > > > > -----Original Message----- > > > From: Symon Thurlow [mailto:[EMAIL PROTECTED]] > > > Sent: Saturday, October 12, 2002 4:45 PM > > > To: [EMAIL PROTECTED] > > > Subject: RE: can I use a /31 subnet to the link between 2 routers eth > > > [7:55469] > > > > > > > > > Thanks! > > > > > > I stand corrected. > > > > > > Cheers, > > > > > > Symon > > > > > > -----Original Message----- > > > From: Bob McWhorter [mailto:[EMAIL PROTECTED]] > > > Sent: 12 October 2002 17:06 > > > To: [EMAIL PROTECTED] > > > Subject: RE: can I use a /31 subnet to the link between 2 routers eth > > > [7:55460] > > > > > > > > > Symon, > > > > > > Reference RFC 3021 > > > > > > Using 31-Bit Prefixes on IPv4 Point-to-Point Links > > > > > > HTH > > > > > > > > > > > > -----Original Message----- > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf > > > Of Symon Thurlow > > > Sent: Saturday, October 12, 2002 7:59 AM > > > To: [EMAIL PROTECTED] > > > Subject: RE: can I use a /31 subnet to the link between 2 routers eth > > > [7:55454] > > > > > > > > > Well, if you work it out: > > > > > > Obviously the first three octets wil be all 1's, so if you look at the > > > > > last octet: > > > > > > 11111110 > > > > > > Which = 254. This only leaves you with 2 addresses per subnet, and > > > since you need one address for the Network address and one for the > > > Broadcast address, you no longer have any addresses you can actually > > > use. > > > > > > A 30 bit subnet, where the last octet= > > > > > > 11111100 > > > > > > Equals 252. This means you have 4 addresses per subnet. Taking away > > > one address for the Network and one for the Broadcast address, this > > > leaves you one address for each end of the link. > > > > > > So I am not sure how you could use a /31. > > > > > > Symon > > > > > > -----Original Message----- > > > From: bbfaye [mailto:[EMAIL PROTECTED]] > > > Sent: 12 October 2002 14:54 > > > To: [EMAIL PROTECTED] > > > Subject: can I use a /31 subnet to the link between 2 routers eth > > > ports. [7:55450] > > > > > > > > > I used thought it shoul be /30 mask subnet... > > > but recently I saw some guy said: use /31 subnet to save the > > > address.... I really confusing me... > > > ###################################################################### > > > ## > > > ############# > > > Scanned for Viruses and Content and cleared by the Webvein Mail > > > Gateway > > > > > ######################################################################## > > > ############# > > > > > ######################################################################## > > > ############# > > > Scanned for Viruses and Content and cleared by the Webvein Mail > > > Gateway > > > > > ######################################################################## > > > ############# > > ######################################################################## > > ############# > > Scanned for Viruses and Content and cleared by the Webvein Mail > > Gateway > > ######################################################################## > > ############# Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=55513&t=55513 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
