Date: Mon, 09 Feb 1998 12:42:34 -0800 From: "Eric C. S. Dynamic" <ecsd@transbay.net> To: Doug White <dwhite@resnet.uoregon.edu> Cc: questions@FreeBSD.ORG Subject: Re: arp question Message-ID: <34DF6A3A.398A68D@transbay.net> References: <Pine.BSF.3.96.980208235055.24904P-100000@gdi.uoregon.edu>
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... not on same network > You're defining your ethernet aliases wrong. Try this: > ifconfig vx0 inet a.b.c+1.2 netmask 0xffffffff alias > Doug White | University of Oregon That worked. (To get the "arp -s" accepted, anyway.) I know this has undoubtedly gone through in thread(s) here, but why can't I alias an interface using the netmask appropriate for that interface? My router is on the network as two different class C's. My host is on the network as a single 512-IP subnet. My notion was to define the host interface so that not only was it primarily the 512-IP interface as required, but also so that it was on the upper class C by itself. I could imagine that the routing would be a bit nonplussed with this, but I could also imagine that the routing would just say, "fine, if you want to do it that way." The reason for doing this is (1) that in order to aggregate the two class C subnets into one on the router, I have to get all my remote users to switch netmasks at once, and that's proved administratively difficult. I can tell the router its netmask is 0xfffffe00, but once I do, all dialups fail somewhere in LCP negotiations until the user(s) change their router configs as well. If I knew they were all paying attention, I could mass-mail them and say "change will occur at 0000GMT on [date]", but they aren't listening and they'll make me nuts with calls as to why isn't it working, etc. But (2), I need the extra class C's addresses to represent virtual domains (out to http/1.0 clients.), and it seems I'd tried to tell my host interface to be two class C's, a.b.c.N mask 0xffffff00 a.b.c+1.N mask 0xffffff00 but that wasn't happy either. I realize that the interface code is getting cleverer, but it didn't seem like I could stack two networks on the same interface. (I'm only using routed, if that matters.) So, when I want to declare the interface as ALSO a.b.c+1.2 with netmask 0xffffff00, that's exactly what I really mean (in the router's behalf) ... and that's illegal? Unfortunately for the router, it has only one ethernet interface. Pissers. thanks. -ecsd p.s. It might be worth mentioning that I've also seen the syndrome of not being able to "see" an aliased interface from the host it's aliased on, as others have reported: ifconfig xy0 1.2.3.4 ifconfig xy0 1.2.3.5 mask (whatever) and can't ping 1.2.3.5 from 1.2.3.4. I've just assumed it's because I'm not running 2.2.5.9999 .... To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe questions" in the body of the message
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