(usr-tc) Three IPs on a dialup?
Hi ya guys... I have a customer who wants three IPs on a dialup. I am thinking this cannot be done with a dialup on a USR TC, Hiper or not, but in an attempt to satisify my morbid sense of trivia... How can a dialup line be set up with three IP addreses routed over it? Needless to say, I suggested they use NAT... Anyway, thanks in advance... ----Steve Stephen Amadei Director of MIS Dandy Connections, Inc. Atlantic City, NJ - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.
Route a /29 subnet to them, which is the smallest block that'll give them at least 3 usable addresses. (8 addresses, 6 usable.) Mike Andrews (MA12) * mandrews@dcr.net * http://www.bit0.com/ VP, sysadmin, & network guy, Digital Crescent Inc, Frankfort KY Internet services for Frankfort, Lawrenceburg, Owenton, & Shelbyville "With sufficient thrust, pigs fly just fine." -- RFC 1925 On Wed, 24 Nov 1999, Stephen Amadei wrote:
Hi ya guys... I have a customer who wants three IPs on a dialup.
I am thinking this cannot be done with a dialup on a USR TC, Hiper or not, but in an attempt to satisify my morbid sense of trivia...
How can a dialup line be set up with three IP addreses routed over it?
Needless to say, I suggested they use NAT...
Anyway, thanks in advance...
- To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.
On Wed, 24 Nov 1999, Mike Andrews wrote:
Route a /29 subnet to them, which is the smallest block that'll give them at least 3 usable addresses. (8 addresses, 6 usable.)
O.K... I guess I can do this through RADIUS, right? Now, subnetting below /24 has always been a weak point for me... and I realise I'm going a bit off topic, but I figure everyone on this list are about as knowledgable in subnetting as I'm going to find. I understand the basic tables of subnets and masks for under a class C. But I have two questions on how to use them. First, lets say I give this dialup a network of 192.168.1.0/29 (assuming 192.168.1.0/24 is a normal, routable class C). The net number is .0 and the broadcast is .7. What I don't understand next is what to do with the rest of the addresses. Can I dump the rest of the addresses onto an existing segment of my network that currently has a class C on it? Would I do it like the following? Internet----Router(200.200.200.1) | ____________ Main Network 200.200.200.0/24 192.168.1.8/29 192.168.1.16/28 192.168.1.32/27 192.168.1.64/26 192.168.1.128/25 ____________ | ____________ Total Control (normally gives out IPs from a pool in 200.200.200.0/24 Gives out a 192.168.1.0/29 ____________ Next, I don't quite understand where I need to apply static routes. I assume I would need to add a static route on the TC for the subnet I give the dialup, but would that subnet also require a routing entry on my router, except for the obvious need for a 192.168.1.0/24 route? Confused... but thanx in advance... ----Steve Stephen Amadei Director of MIS Dandy Connections, Inc. Atlantic City, NJ - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.
It they did a /30 that would give 2 usable and then the static IP to route to would be the third. As long as they don't have 3 seperate boxes to put behind it. Ed Taylor ----- Original Message ----- From: Stephen Amadei To: usr-tc@lists.xmission.com Sent: Wednesday, November 24, 1999 4:32 AM Subject: Re: (usr-tc) Three IPs on a dialup? On Wed, 24 Nov 1999, Mike Andrews wrote:
Route a /29 subnet to them, which is the smallest block that'll give them at least 3 usable addresses. (8 addresses, 6 usable.)
O.K... I guess I can do this through RADIUS, right? Now, subnetting below /24 has always been a weak point for me... and I realise I'm going a bit off topic, but I figure everyone on this list are about as knowledgable in subnetting as I'm going to find. I understand the basic tables of subnets and masks for under a class C. But I have two questions on how to use them. First, lets say I give this dialup a network of 192.168.1.0/29 (assuming 192.168.1.0/24 is a normal, routable class C). The net number is .0 and the broadcast is .7. What I don't understand next is what to do with the rest of the addresses. Can I dump the rest of the addresses onto an existing segment of my network that currently has a class C on it? Would I do it like the following? Internet----Router(200.200.200.1) | ____________ Main Network 200.200.200.0/24 192.168.1.8/29 192.168.1.16/28 192.168.1.32/27 192.168.1.64/26 192.168.1.128/25 ____________ | ____________ Total Control (normally gives out IPs from a pool in 200.200.200.0/24 Gives out a 192.168.1.0/29 ____________ Next, I don't quite understand where I need to apply static routes. I assume I would need to add a static route on the TC for the subnet I give the dialup, but would that subnet also require a routing entry on my router, except for the obvious need for a 192.168.1.0/24 route? Confused... but thanx in advance... ----Steve Stephen Amadei Director of MIS Dandy Connections, Inc. Atlantic City, NJ - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.
Thus spake Ed
It they did a /30 that would give 2 usable and then the static IP to route to would be the third.
As long as they don't have 3 seperate boxes to put behind it.
Problem being...with typical routing setup, you've got one of two scenarios...either the eth0 of the routing box is the static that's assigned "to route to" (using your terminology to help clarify here). Meaning that the static is pulled out of the /30 block, meaning there's only one other address available...one short... Or, you have the static IP "to route to" :), and then the /30 block has to have one of the IP's assigned to the eth0 of the same box doing the routing which means you've got two IP's assigned to the same box...still one short. :/ You could do a couple of /30's and have multiple IP's assigned to the eth0 card of the router....but then you're still chewing up the same amount of space as a single /29 does with fewer useable addresses...it does have the upside of letting you assign non-contiguous addresses if your IP space is that fragmented. -- Jeff McAdams Email: jeffm@iglou.com Head Network Administrator Voice: (502) 966-3848 IgLou Internet Services (800) 436-4456 - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.
Yes as I stated... "As long as they don't have 3 seperate boxes to put behind it." but I should have said to clarify if you have but 1 box on the other side. This would be 2 IP's on the main box which is directly connected and 1 IP on the other. Ed Taylor ----- Original Message ----- From: Jeff Mcadams To: usr-tc@lists.xmission.com Sent: Wednesday, November 24, 1999 9:49 AM Subject: Re: (usr-tc) Three IPs on a dialup? Thus spake Ed
It they did a /30 that would give 2 usable and then the static IP to route to would be the third.
As long as they don't have 3 seperate boxes to put behind it.
Problem being...with typical routing setup, you've got one of two scenarios...either the eth0 of the routing box is the static that's assigned "to route to" (using your terminology to help clarify here). Meaning that the static is pulled out of the /30 block, meaning there's only one other address available...one short... Or, you have the static IP "to route to" :), and then the /30 block has to have one of the IP's assigned to the eth0 of the same box doing the routing which means you've got two IP's assigned to the same box...still one short. :/ You could do a couple of /30's and have multiple IP's assigned to the eth0 card of the router....but then you're still chewing up the same amount of space as a single /29 does with fewer useable addresses...it does have the upside of letting you assign non-contiguous addresses if your IP space is that fragmented. -- Jeff McAdams Email: jeffm@iglou.com Head Network Administrator Voice: (502) 966-3848 IgLou Internet Services (800) 436-4456 - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.
On Wed, 24 Nov 1999, Stephen Amadei wrote:
On Wed, 24 Nov 1999, Mike Andrews wrote:
Route a /29 subnet to them, which is the smallest block that'll give them at least 3 usable addresses. (8 addresses, 6 usable.)
O.K... I guess I can do this through RADIUS, right?
Yeah. Where you'd normally have Framed-IP-Address = 255.255.255.254, Framed-IP-Netmask = 255.255.255.255, you'd put instead something like this: Framed-IP-Address = 192.168.1.0, Framed-IP-Netmask = 255.255.255.248,
First, lets say I give this dialup a network of 192.168.1.0/29 (assuming 192.168.1.0/24 is a normal, routable class C). The net number is .0 and the broadcast is .7. What I don't understand next is what to do with the rest of the addresses. Can I dump the rest of the addresses onto an existing segment of my network that currently has a class C on it? Would I do it like the following?
Internet----Router(200.200.200.1) | ____________ Main Network 200.200.200.0/24 192.168.1.8/29 192.168.1.16/28 192.168.1.32/27 192.168.1.64/26 192.168.1.128/25 ____________ | ____________ Total Control (normally gives out IPs from a pool in 200.200.200.0/24 Gives out a 192.168.1.0/29 ____________
Looks fairly reasonable. You don't *have* to shove all those extra blocks onto a single LAN though... you don't have to shove 'em anywhere if you aren't really using them yet. Just save them for when you get some dedicated T1 customers that need some smallish blocks of IP space.
Next, I don't quite understand where I need to apply static routes. I assume I would need to add a static route on the TC for the subnet I give the dialup, but would that subnet also require a routing entry on my router, except for the obvious need for a 192.168.1.0/24 route?
If you're running RIPv2 or OSPF, and have it set up right, you shouldn't need ANY static routes. If you've got 2 or 3 TC's handling the same dialup pool (say for example you had 20 PRI's at one POP)... then static routes on your TC or your upstream are kinda useless because you don't know which TC they're going to hit on any given day/hour/whatever... so you really can't use static routes there anyway. When your 192.168.0.9/29 user dials in, the route gets added to the TC's routing table automatically (when it's told the route by Radius, basically). So that part you don't have to worry about at all. Then it's up to RIPv2 or OSPF to advertise that route to the rest of your network, and to drop the announcement when they hang up. Your regular IP pools are supposed to be advertised the same way, but in practice I never really got it working with RIPv2. (To be honest I didn't really TRY very hard. :) With OSPF it works great though. Just add the pool and all the Ciscos see it automatically. Delete a pool and the Ciscos drop that too. Mike Andrews (MA12) * mandrews@dcr.net * http://www.bit0.com/ VP, sysadmin, & network guy, Digital Crescent Inc, Frankfort KY Internet services for Frankfort, Lawrenceburg, Owenton, & Shelbyville "With sufficient thrust, pigs fly just fine." -- RFC 1925 - To unsubscribe to usr-tc, send an email to "majordomo@xmission.com" with "unsubscribe usr-tc" in the body of the message. For information on digests or retrieving files and old messages send "help" to the same address. Do not use quotes in your message.
participants (4)
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Ed -
Jeff Mcadams -
Mike Andrews -
Stephen Amadei