From owner-freebsd-isp Thu Nov 12 20:32:21 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id UAA19219 for freebsd-isp-outgoing; Thu, 12 Nov 1998 20:32:21 -0800 (PST) (envelope-from owner-freebsd-isp@FreeBSD.ORG) Received: from kjsl.com (Limpia.KJSL.COM [198.137.202.3]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id UAA19214 for ; Thu, 12 Nov 1998 20:32:20 -0800 (PST) (envelope-from javier@kjsl.com) Received: (from javier@localhost) by kjsl.com (8.8.5/8.8.5) id UAA22947; Thu, 12 Nov 1998 20:30:40 -0800 (PST) Date: Thu, 12 Nov 1998 20:30:40 -0800 (PST) Message-Id: <199811130430.UAA22947@kjsl.com> From: Javier Henderson MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: Bill Vermillion Cc: freebsd-isp@FreeBSD.ORG Subject: Re: two routers back to back: Do they need real ip-adresses? In-Reply-To: <199811130403.XAA21999@bilver.magicnet.net> References: <199811130403.XAA21999@bilver.magicnet.net> X-Mailer: VM 6.33 under Emacs 19.34.1 Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Bill Vermillion writes: > Leif Neland recently said: > > We had to put in a cisco 1605 router (with 2 ethernet ports) between our > > net and our isp supplying our backbone connection. > > > The "ethernet", which is only a crossed 10BT cable between the two > > routers, does it need real ip adresses? > > > > > > +-----------+ +-----------+ +----+ ----- > > --our net---+ E0 E1 +------+ E0 S0 |-----+ | \ > > 3C's | 1605 | | 100x | | +---- > > +-----------+ ^ +-----------+ +----+ > > | > > Can I use 192.168.1.0-adresses here? > > Or even unnumbered ip? > > As long as both routers know about the other and it is an ethernet > connection - just hook them together. I did that in the process of > moving 4 C's from one provider to another. It made it convenient > and then I could upgrade the IOS on the first. I'm trying to understand why you want the 1605 in place. Can't you just connect "our net of 3C's" to Ethernet 0 on the first router (the one with Serial0 connectd to your ISP)? > > Our uplink isp wants us to subnet one of our C's in a /30, is this > > really nessecary? > > That's typically the address of the serial port. A /30 gives a > four address range. The network number, 2 IPS, and a broadcast > number. The ones I've seen have the ISP as the lower of the two > addresses and the client as the upper of the two. These normally > are not part of your address space. The above is correct, though your ISP probably wants you to use numbered links so packets generated by either router have an IP source address of the interface from which they are leaving the router. This can help troubleshoot certain network problems. -jav To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message